feat: add support for hugging face tokenizers, add executorch and tokenizers as submodules

[NorbertKlockiewicz]

Description

This PR introduces support for hugging face tokenizers by utilizing cpp bridge that connects native code with hf tokenizers library. It also features configured submodules which point to our executorch and tokenizers-cpp repositories that are stored in software mansion labs organization.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update (improves or adds clarity to existing documentation)

Tested on

• iOS
• Android

Testing instructions

Screenshots

Related issues

Checklist

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have updated the documentation accordingly
• My changes generate no new warnings

Additional notes