[FGA-98] Add schema convert and schema apply to FGA module

[atainter]

Usage:
Convert a schema to json

workos fga schema convert ./schema.txt --to json 

Write to a file

./bin/workos-cli fga schema convert ./schema.txt --to json --output raw > test.json

Apply a schema

workos-cli fga schema apply ./schema.txt

Apply a schema with verbose output and fail on warnings

workos-cli fga schema apply ./schema.txt -v --strict

[linear]

FGA-98 Update CLI to convert and apply schemas