feat: Create change requests for segments

[zachaysan]

Changes

This PR works in concert with this other PR on the workflows repo.

This PR introduces many changes to support the addition of segments in change requests. The primary logic around transferring change request segment data into the target segment data involves re-using logic that was originally written for the segment versioning.

Due to the primary manager (.objects) now including versioned or change requested segments copies, some amount of work was necessary to get all the aspects of the existing code to pass. The .live_objects manager is used for segments that are not merely versions or change request segments but in some places manually filtering segments was the only solution.

How did you test this code?

Added tests across the test suite, including new tests for duplicate segments to test filtering, as well as tests located in with the other workflows PR to get coverage of edge cases.