deprecate Bits

[sequencer]

Based on the disscussion on the dev-meeting. Bits will return UInt, which is a strange API, I think we need to remove this API. Then adding it back after making abstract class Bits concrete.

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

• code cleanup

API Impact

deprecate API

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

Bits(???) is deprecated.

Reviewer Checklist (only modified by reviewer)

• [ ] Did you add the appropriate labels?
• [ ] Did you mark the proper milestone (3.2.x, 3.3.x, 3.4.0, 3.5.0) ?
• [ ] Did you review?
• [ ] Did you check whether all relevant Contributor checkboxes have been checked?
• [ ] Did you mark as Please Merge?