Refactoring: Rename FieldMapper.termsFilter to fieldDataTermsFilter.

FieldMapper has two methods
`Filter termsFilter(List values, @Nullable QueryParseContext)` which is supposed
to work on the inverted index and
`Filter termsFilter(QueryParseContext, List, QueryParseContext)` which is
supposed to work on field data. Let's rename the second one to
`fieldDataTermsFilter` and remove the unused `QueryParseContext`.

Close #6888
[Infra] remove indicesLifecycle.Listener from IndexingMemoryController

The IndexingMemoryController determines the amount of indexing buffer size and translog buffer size each shard should have. It takes memory from inactive shards (indexing wise) and assigns it to other shards. To do so it needs to know about the addition and closing of shards. The current implementation hooks into the indicesService.indicesLifecycle() mechanism to receive call backs, such shard entered the POST_RECOVERY state. Those call backs are typically run on the thread that actually made the change. A mutex was used to synchronize those callbacks with IndexingMemoryController's background thread, which updates the internal engines memory usage on a regular interval. This introduced a dependency between those threads and the locks of the internal engines hosted on the node. In a *very* rare situation (two tests runs locally) this can cause recovery time outs where two nodes are recovering replicas from each other.

 This commit introduces a a lock free approach that updates the internal data structures during iterations in the background thread.

Closes #6892
Revert "Netty: Refactoring to make MessageChannelHandler extensible"

This results in unstable tests, most likely due to Channels being mixed
up by wrongly creating the pipelines. Needs investigation and a test.

This reverts commit db7f0d36af6692b1648cbea6e1e7147e7cfa70dc.
CORS: Support regular expressions for origin to match against

This commit adds regular expression support for the allow-origin
header depending on the value of the request `Origin` header.

Relates #5601
Closes #6891