refactor(ui): sync theme with figma

[xsahil03x]

PR Description

This PR sync the theme colors with the figma.

[codecov]

Codecov Report

Attention: Patch coverage is 96.55172% with 1 line in your changes missing coverage. Please review.

Please upload report for BASE (v10.0.0@d7f1b09). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
...stream_chat_flutter/lib/src/theme/color_theme.dart	93.33%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             v10.0.0    #2263   +/-   ##
==========================================
  Coverage           ?   63.41%           
==========================================
  Files              ?      399           
  Lines              ?    25109           
  Branches           ?        0           
==========================================
  Hits               ?    15924           
  Misses             ?     9185           
  Partials           ?        0           

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