* [REFACTOR][OBJECT] Consoldiate NodePtr/Ref/Hash/Equal and macros to Object.

Historically, we have classes like NodePtr/Ref/HashEqual.
After unified object protocol, these names are just alias of the object counterpart.
Moreover, there are helper macros defined over the places for defining these object.

This PR consoldiate the terminologies into the corresponding ones
in the Object system so we have a clean and consistent API moving forward.

* Update include/tvm/attrs.h

Co-Authored-By: Wei Chen <ipondering.weic@gmail.com>

* fix compilation

Co-authored-by: Wei Chen <ipondering.weic@gmail.com>

* Refactor to use IsOp utility

* retrigger CI

dtype.h -> runtime/data_type.h

Changes:
- Rename all old reference of tvm::Type to DataType
- ExprNode.type -> ExprNode.dtype
- Expr.type() -> Expr.dtype()
- Change Expr related functions to expr_operator.
  - DataType::min() -> min_value(DataType)
  - DataType::max() -> max_value(DataType)
- Move type constructor Int, UInt, Float, Handle, Bool into DataType.
  - Int(bits) -> DataType::Int(bits)
  - UInt(bits) -> DataType::UInt(bits)

* [LINT] Improve the check tool to handle ASF copyright message.

* [LINT] Remove unnecessary copyright message as per ASF requirement.

* Fix codegen hybrid

* [LINT] Broaden license checks to include html, xml

* [LINT] Fix rest of the files

* Fix notice

* [LINT] Improve check file type error message

* [Relay][Pass] Avoid FoldConstant folding some ops

* rename

* [REFACTOR][NODE][RUNTIME] Move Node to the new Object protocol.

This PR removes the original node system, and make node as a subclass of Object.
This is a major refactor towards a better unified runtime object system.

List of changes in the refactor:

- We now hide data_ field, use Downcast explicitly to get a sub-class object.
- Removed the node system FFI in python.
- Removed the node C API, instead use PackedFunc for list and get attrs.
- Change relay::Op::set_attr_type_key(attr_key_name) to relay::Op::set_attr_type<AttrType>().
  - This change was necessary because of the new Object registration mechanism.
  - Subsequent changes to the op registrations
  - The change revealed a few previous problems that is now fixed.
- Patched up a few missing node type registration.
  - Now we will raise an error if we register object that is not registered.
- The original node.h and container.h are kept in the same location.
- Calling convention: kObjectHandle now equals the old kNodeHandle, kNodeHandle is removed.
- IRFunctor now dispatches on ObjectRef.
- Update to the new type checking API: is_type, derived_from are replaced by IsInstance.
- Removed .hash member function, instead use C++ convention hasher functors.

* Address review comments

* Refactor.

* update

* update

* update

* update

* update

* update

* [relay][frontend] Return Module from get_workload

* pass entry_func to autotvm

* disable tune

* add property to module

* mod.entry_func to main

* .main -> mod["main"]

* fix

* Implement the virtual machine

Co-Authored-By: wweic <ipondering.weic@gmail.com>

* Fix rebase build issues

* Reorganize vm.py and fix allocator bug

* Remove compiler

* Remove tests

* Remove backend/vm/vm.cc too

* Fix docs

* Fix doc

* Fix doc

* Add vm docs

* Remove change to dead_code.cc

* Remove Relay logging

* Remove reduce

* Update include/tvm/runtime/vm.h

Co-Authored-By: jroesch <roeschinc@gmail.com>

* Reformat

* Update include/tvm/runtime/vm.h

Co-Authored-By: jroesch <roeschinc@gmail.com>

* Address feedback

* Update include/tvm/runtime/vm.h

Co-Authored-By: jroesch <roeschinc@gmail.com>

* Apply suggestions from code review

Co-Authored-By: jroesch <roeschinc@gmail.com>

* Fix a couple outstanding comments

* Last couple comments

* Update include/tvm/runtime/vm.h

Co-Authored-By: jroesch <roeschinc@gmail.com>

* Address code review feedback

* Fix final comment

* Address comments

* Error reporting and example

* add Const

* Explicitly delete copy assignment operator

* Fix rebase

* Pass 3rd arg to fusion

* Add Relay compiler pass tutorial docs

* Add Python API hook wrapping step

* Incorporate feedback

* More doc iteration

* Mooooore iteration

* Rewrite `runtime.md` in rst

* Add `set_body_simple` to Registry, refactor a lot of code to use it

* Add more types to Relay PackedFuncs

* Add Registry::set_body_method to easily make Node methods into
PackedFuncs

* Add set_body_method, set_body_node_method; start typing api_lang

* Add some docs, remove unused script

* Fix mysterious linter problem

* Touch up api_ir.cc

* Fix some issues with TOPI argument counts

* Revert changes to topi.cc to avoid problems with optional arguments

* A little more cleanup

* Type more of the api _ functions

* Whitespace

* Finalize names and docs for new registry helpers

* Update docs

* [HEADER] ASF header dir=include

* [HEADER] ASF Header dir=src

* [HEADER] ASF Header -dir=python

* [HEADER] ASF header dir=topi

* [HEADER] ASF Header dir=nnvm

* [HEADER] ASF Header -dir=tutorials

* [HEADER] ASF Header dir=tests

* [HEADER] ASF Header -dir=docker

* fix whitespace

* [HEADER] ASF Header -dir=jvm

* [HEADER] ASF Header -dir=web

* [HEADER] ASF Header --dir=apps

* [HEADER] ASF Header --dir=vta

* [HEADER] ASF Header -dir=go

* temp

* [HEADER] ASF Header --dir=rust

* [HEADER] Add ASF Header --dir=cmake

* [HEADER] ASF Header --dir=docs

* [HEADER] Header for Jenkinsfile

* [HEADER] ASF Header to toml and md

* [HEADER] ASF Header to gradle

* Finalize rat cleanup

* Fix permission

* Fix java test

* temporary remove nnvm onnx test

* Add shapeof op in topi

* Add relay shape_of op

* Add constant folding for shape_of

* Allow shape op to specify dtype

* Add mxnet converter for shape_array

* lint

* lint

* Add doc