Uniform API: Subscriptions are deleted if distributor reregisters itself with a different integration/distributor version

[bacherfl]

The root cause lies in the following code:

keptn/shipyard-controller/handler/uniformintegrationhandler.go

Line 147 in 81d807d

rh.uniformRepo.CreateOrUpdateUniformIntegration(*integration)

here, it is checked if the version of the uniform integration and/or of its distributor has changed in order to update them (see #5517 for more context). However, this overwrites the complete uniform integration and its subscriptions, which explains why the subscriptions were empty after an upgrade of Keptn and/or integration.