- event expressions use Expr over LHS
- stricter AST representation of event controls
- property specs use event expressions directly

Specifically, support has been added for non-ANSI style port
declarations where the port declaration is separate from the
corresponding net or variable declaration.

- all inputs are now decoded as UTF-8, regardless of the platform
- decoding failures are now tolerated via transliteration given errant
  characters are generally expected to appear in comments

This works around a compilation performance regression in GHC 9.0.1:
https://gitlab.haskell.org/ghc/ghc/-/issues/20261. This also speeds up
compilation on other versions.

This adds support for typed valued parameters declared in parameter port
lists without explicitly providing a leading `parameter` or `localparam`
marker.

- use iverilog's -gstrict-expr-width throughout test suite
- add warnings for excess bits or padding zeroes in number literals
- add new --oversized-numbers parameter to retain support for unsized
  numbers wider than 32 bits
- localized use of oversized numbers to new truncate test suite which
  verifies the behavior of both modes, and compares against the known
  behavior of iverilog

- detect and forbid non-positive size casts
- detect and forbid negative struct pattern literal indices
- avoid invalid constant folding of negative based literals

- add unified frontend configuration record to make adding future
  options easier
- use ExceptT throughout, rather than using runExceptT at internal
  boundaries

- updated representation and added codegen for sequence match items
- fix incorrect codegen for `iff` property expression

- convert loops with no or many incrementations
- restrict AST node to only contain traditional initializations
- parser elaborates for loop decls into a synthetic block
- decl list codegen is now specific to parameter decl lists
- update jump conversion special cases for new representation
- first experiments with bimapM

- remove needless comments generated during interface conversion
- filter null statements even in verbose mode
- hoist trace comment statements if doing so would prevent the need to
  wrap a task or function body in a block
- add traces for global declarations
- add traces for parameter declaration lists
- add traces for module items within generate blocks
- avoid generating duplicate traces before declarations