Implement codegen using protobufs

[daniellionel01]

This library is not usable as an actual plugin inside of a sqlc.yml configuration since it does not implement using protobufs.

It remains an open question wether the gleam ecosystem is sufficient to work with protobufs or if there are elixir libraries usable through FFI.

If we were to make parrot a usable sqlc plugin we could probably get listed on this page as a community plugin: https://docs.sqlc.dev/en/stable/reference/language-support.html

References:

• Addition to https://docs.sqlc.dev/en/stable/reference/language-support.html #24
• [RFC] Added Gleam Community Project to docs - language-support.rst sqlc-dev/sqlc#4012