refactor(theme): themes flexibility

[stackchain]

• Covered with 100% tests
• Renamed to use Tailwind CSS selectors (1 update is needed on Figma)
• Added storage (selecting will persist)
• Added detectTheme - will resolve from 'system' if empty and 'sytem' now is also a valid option
• Refactored tokens (not liking the current definition) specially lineHeight
• Renamed from - to _ so it can be accessed
• Added tiny README.md
• useTheme is designed to manage theme selection not to be consumed by the UI
• useThemeColor is designed to consume colors
• Moved from calculated to static
• Split Palette into Base (dark/light) and Theme (exposed officially used)

It is using as const therefore making the properties read-only I'm guessing react-native will complain, it can leverage Writable or Draft from 'immer'

[stackchain]

@SorinC6 can you take it from here? It will require an update on wallet-mobile, big one.

• Fix initialization (a storage is required, check Portfolio for example)
• Fix consume from useTheme -> useThemeColor
• Fix styles (need to import atoms) to everything that is not theme (color) based
• Fix styles colors

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It could also export from Theme the atoms, yet, IMHO is an overkill, unless is planned a compact / big version.

[stackchain]

@SorinC6 please check with Design, if they approve the Base->Theme palette naming convention we can go on with the implementation