Refactor Annotation of StrongEnum.

[sequencer]

This PR refactor StrongEnum to use CustomRadixTransform in chipsalliance/firrtl#2434. Original API was deprecated in #2240

Contributor Checklist

• [ ] Did you add Scaladoc to every public function/method?
• [ ] Did you add at least one test demonstrating the PR?
• [ ] Did you delete any extraneous printlns/debugging code?
• [ ] Did you specify the type of improvement?
• [ ] Did you add appropriate documentation in docs/src?
• [ ] Did you state the API impact?
• [ ] Did you specify the code generation impact?
• [ ] Did you request a desired merge strategy?
• [ ] Did you add text to be included in the Release Notes for this change?

Type of Improvement

• backend code generation

API Impact

StrongEnum not generate CustomRadix{Def,Apply}Annotation

Backend Code Generation Impact

None

Desired Merge Strategy

• Rebase: You will rebase the PR onto master and it will be merged with a merge commit.

Release Notes

Reviewer Checklist (only modified by reviewer)

• [ ] Did you add the appropriate labels?
• [ ] Did you mark the proper milestone (Bug fix: 3.3.x, [small] API extension: 3.4.x, API modification or big change: 3.5.0)?
• [ ] Did you review?
• [ ] Did you check whether all relevant Contributor checkboxes have been checked?
• [ ] Did you mark as Please Merge?

[sequencer]

ask @jackkoenig to see if this changing is appropriate. If true, I'll continue fixing the tests.

[sequencer]

blocked by #2310