feat: Add MDA progress widget

[tlambert03]

Work in progress. will add something like this to monitor the progress of an MDA Sequence

Screen.Recording.2024-01-31.at.10.57.23.AM.mov

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 177 lines in your changes are missing coverage. Please review.

Project coverage is 89.67%. Comparing base (5a91d84) to head (c6310d5).

❗ Current head c6310d5 differs from pull request most recent head f030aff. Consider uploading reports for the commit f030aff to get more accurate results

Files	Patch %	Lines
src/pymmcore_widgets/mda/_progress_widget.py	0.00%	177 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #268      +/-   ##
==========================================
- Coverage   91.56%   89.67%   -1.89%     
==========================================
  Files          69       69              
  Lines        8982     8992      +10     
==========================================
- Hits         8224     8064     -160     
- Misses        758      928     +170     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.