Allow to enable / disable bloom filter loading on an index
Allow to have a new index level setting index.codec.bloom.load (default to true), that can control if the boom filters will be loaded or not. This is an updateable setting, that can be updated on a live index using the update settings API.

Note though, when this setting is updated, a fresh Lucene index will be reopened, causing associate caches to be dropped potentially.

closes #4525

Note, this change also disables the returning lucene ram usage stats, due to a bug in Lucene, relates to #4512