Mount services REST endpoints as integrations endpoints

What does this MR do and why?

As part of the effort to rename "services" to "integrations" throughout the codebase, this duplicates the REST API routes so that it is available under both the /services and /integrations endpoints.

This replaces the previous MR !67347 (closed) from @rukkykofi, thanks again for your contribution! 🙇

Issue: #334500 (closed)

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

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