Support dynamic colors

[sizzlesloth]

Ideally I wanted to make the least changes necessary to support dynamic colors, but also keep what exists as a fallback.

Note:
I intended to change the most visible front-facing colors, keeping minor details (SMS error text, etc.) the defaults. I have no artistic talent whatsoever, so feel free to change the coloring of minor details if you wish.

Changes

• Add com.google.android.material:material:1.13.0 dep
• Add a values-v31/colors.xml file using token colors
• Renamed some icon size attributes to amend naming conflicts with new dep

Out of scope

• Changing components from appcompat to material3
• Changing graphical asset colors (for example, the 'selection tick' icon is still green, when long-pressing on a conversation list item)