Remove unused/redundant assets.

[pixlwave]

This PR does the following:

• Remove old image assets that are no longer used in the app.
• Remove an old brand-color asset that was only used in the Migration/Waitlist screens and is no longer necessary (I think theres a colour token for this in one way or another now).
• Remove a grabber colour which after checking the component in Compound I saw was simply a copy of the system tertiary colour.

[github-actions]

	Warnings
⚠️	You seem to have made changes to views. Please consider adding screenshots.

Generated by 🚫 Danger Swift against fe5d952

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 78.70%. Comparing base (a70189d) to head (fe5d952).
Report is 4 commits behind head on develop.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...mScreen/ComposerToolbar/View/MessageComposer.swift	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #3702      +/-   ##
===========================================
- Coverage    78.72%   78.70%   -0.03%     
===========================================
  Files          792      792              
  Lines        67839    67826      -13     
===========================================
- Hits         53409    53381      -28     
- Misses       14430    14445      +15     

Flag	Coverage Δ
unittests	70.22% <0.00%> (-0.01%)	⬇️

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