refactor: remove branding folder

[kathaypacific]

Description

This PR:

1. remove branding folder and move all assets to the intended android, ios, src directories
2. in the images folder, put all .png files in an assets sub folder. these images continue to be exported from Images.ts.
3. move "branded" components from icons to images - these are all files that use custom colours, but eventually should be all icons that are not generic (e.g. Material UI icons)
4. remove branding script and references to it

Test plan

n/a

Related issues

• Fixes RET-1156

Backwards compatibility

Y

Network scalability

If a new NetworkId and/or Network are added in the future, the changes in this PR will:

• Continue to work without code changes, OR trigger a compilation error (guaranteeing we find it when a new network is added)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 87.28%. Comparing base (dcbd86e) to head (159d88a).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5813      +/-   ##
==========================================
- Coverage   87.28%   87.28%   -0.01%     
==========================================
  Files         737      737              
  Lines       31183    31178       -5     
  Branches     5222     5222              
==========================================
- Hits        27218    27213       -5     
  Misses       3920     3920              
  Partials       45       45              

Files	Coverage Δ
src/backup/BackupIntroduction.tsx	90.00% <100.00%> (ø)
src/brandingConfig.ts	100.00% <ø> (ø)
src/components/BeatingHeartLoader.tsx	92.30% <100.00%> (ø)
src/dappsExplorer/DappCard.tsx	100.00% <100.00%> (ø)
src/earn/EarnDepositBottomSheet.tsx	98.59% <100.00%> (ø)
src/earn/EarnInfoScreen.tsx	98.03% <100.00%> (ø)
src/home/NotificationBox.tsx	88.65% <100.00%> (ø)
src/images/Blob.tsx	100.00% <ø> (ø)
src/images/GuideKeyHomeCardIcon.tsx	100.00% <ø> (ø)
src/images/GuideKeyIcon.tsx	100.00% <ø> (ø)
... and 50 more

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[bakoushin]

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