Migrate Reanimated 2 code to TS

[jakub-gonet]

Description

Rename all files to .ts extension and serve them from the lib/ directory.
This prepares Reanimated v2 to be rewritten in TS.

Test code and steps to reproduce

Tested on example app and manually investigated files in lib/ directory.

Checklist

• Included code example that can be used to test this change
• Updated TS types
• Added TS types tests
• Added unit / integration tests
• Updated documentation
• Ensured that CI passes

[kacperkapusciak]

• every file inside src/reanimated2 ends with .ts
• code works

[piaskowyk]

Everything looks fine.