Remove unit selection from slider and use defaultValue

[manivoxel51]

What changes are proposed in this pull request?

• don't show the unit dropdown after chat with design - use % for now and wait for feedback
• uncontrolled slider - use defaultValue instead of value prop

How is this patch tested? If it is not, please explain why.

Release Notes

Is this a user-facing change that should be mentioned in the release notes?

• [ ] No. You can skip the rest of this section.
• [ ] Yes. Give a description of this change to be included in the release notes for FiftyOne users.

(Details in 1-2 sentences. You can just refer to another PR with a description if this PR is part of a larger change.)

What areas of FiftyOne does this PR affect?

• [ ] App: FiftyOne application changes
• [ ] Build: Build and test infrastructure changes
• [ ] Core: Core fiftyone Python library changes
• [ ] Documentation: FiftyOne documentation changes
• [ ] Other

Summary by CodeRabbit

• New Features
  • Standardized percentage formatting for slider inputs with updated labels ("Min %" and "Max %").
  • Removed unit selection option from slider input fields.
• Bug Fixes
  • Improved handling and validation of percentage values in input fields.