HSEARCH-472 Deprecating IndexShardingStrategy, removing ShardIdentifer#getShardIdentifiers and changing return values for methods returning String[] to Set<String>, updating javadocs
HSEARCH-1414 Removing similarity checks from the document builders and type metadata. Only point where similarity is now determined is IndexManagerHolder.
Also changing contract of IndexManager by removing setSimilarity() and adding Similarity to initialize().
Improving error messages and updating tests
HSEARCH-1414 Deprecating @Similarity for Search 4.4. To be removed in Search 5.