[TEST] an active shard might also be relocating
[TEST] Add SuppressSysoutChecks to DistributorDirectoryTest
[TEST] Temporarily ignore transport update tests.
Aggregations: Track scores should be applied properly for `top_hits` aggregation.

Closes #6934
[TEST] top_hits aggs with breath_first collect mode only fails if scoring is used (score based sort or track_scores)
Docs: Update documentation about execution hints for the terms aggregation.
[RESTORE] Fail restore if snapshot is corrupted

today if a snapshot is corrupted the restore operation
never terminates. Yet, if the snapshot is corrupted there
is no way to restore it anyway. If such a snapshot is restored
today the only way to cancle it is to delete the entire index which
might cause dataloss. This commit also fixes an issue in InternalEngine
where a deadlock can occur if a corruption is detected during flush
since the InternalEngine#snapshotIndex aqcuires a topLevel read lock
which prevents closing the engine.