This PR handles the case where a single strategy is used in multiple
change requests. Instead of listing the strategy several times in the
output, we consolidate the entries and add a new `changeRequestIds`
property. This is a non-empty list that points to all the change
requests it is used in.
This is required for us to be able to link back to the change requests
from the UI overview.
This change is just a refactor, removing code that's no longer used. Instead of
checking just whether a segment is in use, we now extract the list of
strategies that use this segment. This is slightly more costly,
perhaps, but it will be necessary for the upcoming implementation.
This PR adds the ability to detect which strategies use a specific
segment in active change requests.
It does not wire this functionality up to anything just yet. Follow-up
PRs will integrate this with the segment service and eventually with the
front end.
This PR hooks up the changes introduced in #5301 to the API and puts
them behind a feature flag. A new test has been added and the test setup
has been slightly tweaked to allow this test.
When the flag is enabled, the API will now not let you delete a segment
that's used in any active CRs.
