Migrate compiler public API to TR namespace

[0xdaryl]

Per the discussion and resolution in #3306, the TR namespace shall be used for the public API of the compiler component that is consumable by downstream projects. This umbrella epic will track the work to migrate the existing API to the TR namespace. This work is not expected to be completed with a single PR.

This work includes replacing identifiers with the TR_ prefix in the global namespace and moving them to the TR namespace.

When creating PRs, please reference this issue in the pull request message (i.e., Issue: #3519).