Modularize TypeSpec spec files.

[Devon-White]

Currently when someone clones our repo, they will be using our server urls that are set in the REST API spec.

We need to find a solution to make the URL configurable through a .env file or implement the solution mentioned in this ticket: microsoft/typespec#2916

Additional Notes

We also have some spec files that have not been converted to TypeSpec yet. So a question of needing to create a solution to handle these or wait for them to be converted to TypeSpec also needs to be considered.