What is this feature?
Adds target datasource UID to the recording rules so that they write to the same datasource used for alerting rule queries after the import.
Why do we need this feature?
Target datasourse support was added in #101678, and under a feature flag grafanaManagedRecordingRulesDatasources (#101778).
This PR makes the importing process:
Check if the import contains recording rules
Verify both recording rules and the grafanaManagedRecordingRulesDatasources feature flag are enabled
If either check fails, return an error
If both checks pass, create recording rules with the provided datasource UID set as both the query and target datasource
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