Added specific log level to check which shards were refreshed and which shards we searched on
Introduced common test methods in MatchedQueriesTests (e.g. createIndex, ensureGreen, refresh, assertHitCount)
Fix several places where resources are not closed

This commit adds a test that checks that we are closing
all files even if there are random IOExceptions happening. The test
found several places where due to IOExceptions streams were not
closed due to unsufficient exception handling.
CompletionFieldMapper should use index name instead of full name

Fixes #3669