Add new battery percentage indicator

[tadeubas]

What is this PR for?

• Adds a new battery percentage indicator that updates approximately every 5 seconds

Note: In rare cases, such as when the user briefly connects and disconnects the charger with a low battery, the displayed value may be inaccurate for about a minute. Most of the time, the feature works as expected.

Changes made to:

• Code
• Tests
• Docs
• CHANGELOG

Did you build the code and tested on device?

• Yes, build and tested on Amigo, Cube, M5StickV

What is the purpose of this pull request?

• Bug fix
• New feature
• Docs update
• Other

[codecov]

Codecov Report

❌ Patch coverage is 55.17241% with 13 lines in your changes missing coverage. Please review.
✅ Project coverage is 97.30%. Comparing base (b748413) to head (54ed2d6).

Files with missing lines	Patch %	Lines
src/krux/pages/__init__.py	10.00%	9 Missing ⚠️
src/krux/input.py	80.00%	2 Missing ⚠️
src/krux/krux_settings.py	77.77%	2 Missing ⚠️

❌ Your patch check has failed because the patch coverage (55.17%) is below the target coverage (95.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #805      +/-   ##
===========================================
- Coverage    97.38%   97.30%   -0.09%     
===========================================
  Files           83       83              
  Lines        10548    10565      +17     
===========================================
+ Hits         10272    10280       +8     
- Misses         276      285       +9     

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[qlrd]

LGTM, i will test here