* Fix unreachable code warning by changing match order

Simulation Statements did not previously extend IsDeclaration, but now
they do so their match blocks need to be above IsDeclaration.

* Handle MemoryNoInit case in RtlilEmitter

* Remove use of deprecated logToFile

* Fix uses of LegalizeClocksTransform

Replaced all uses of LegalizeClocksTransform with
LegalizeClocksAndAsyncResetsTransform.

* Remove use of CircuitForm in ZeroWidth

Also remove all related APIs:

ComposableOptions
HasParser
CommonOptions
HasCommonOptions
FirrtlExecutionOptions
HasFirrtlOptions
FirrtlExecutionResult
FirrtlExecutionSuccess
FirrtlExecutionFailure
ExecutionOptionsManager
firrtl.stage.DriverCompatibility.firrtlResultView
logger.Logger.makeScope
OutputConfig
SingleFile
OneFilePerModule

* Change default LogLevel to None which means "unset"

Logger.getGlobalLevel then returns LogLevel.Warn when the current value
is LogLevel.None. This preserves the behavior of the default being
"Warn" but now uses LogLevel.None to indicate "I'm not setting the
value." This resolves issues where it was not possible to tell if
annotations were actually setting the log level or if the default level
of warn was just being filled in.

Co-authored-by: sinofp <sinofp@tuta.io>
Co-authored-by: Jack Koenig <koenig@sifive.com>

With Stage/Phase, users can provide complex functionality at the phase
level rather than just the transform level. It is useful to have the
same logging information at that level. Note that this change still logs
transforms in the same way, but now the time in inclusive of annotation
renaming which can also [unfortunately] be slow.

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

* Check Unidoc on all versions of Scala

  It is required for publishing and we publish every version

* Fix conflicting cross-version suffixes issue

  When running `sbt ++2.13.4 unidoc`, SBT would set the Scala version
  for the fuzzer and benchmark projects even though they aren't really
  relevant to the command. This may be a misconfiguration or a bug in
  the unidoc plugin. Whatever the case, simply making it possible for
  them to use the same version of Scala as the firrtl project (on which
  they depend) fixes the issue.

* Match versions of Scala in build.sbt and CI

* Fix unidoc issues in 2.13.4

  There is some bug in ScalaDoc not finding some links in firrtl.options
  so those links were made absolute as a workaround.

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

* split big Emitter to submodules.

* fix all deprecated warning.

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>