optimize applyDeletes event
- reuse set
- don't copy over again the shard ids immutable set
optimize guice injector once created

in guice, we always use eager loaded singletons for all modules we create, thus, we can actually optimize the memory used by injectors by reduced the construction information they store per binding resulting in extensive reduction in memory usage for many indices/shards case on a node

 also because all are eager singletons (and effectively, read only), we can not go through trying to create just in time bindings in the parent injector before trying to craete it in the current injector, resulting in improvement of object creations time and the time it takes to create an index or a shard on a node
properly reuse indices analyzers
don't wrap in AnalysisService the indices analyzers we have with a NamedAnalyzer, since its effectively creates a new instance of an analyzer (with per field reuse strategy) and we don't benefit as much from reusing analyzers on the indices / node level

Now, the indices level analyzers return a NamedAnalyzer, also NamedAnalyzer will use the non per field reuse strategy since thats really the common case for it (no need for per field reuse there).

Also, try and reuse numeric analyzers globally instead of creating them per numeric mapper. Although those analyzers are not used during indexing (we have a custom numeric field for it), they can be used sometimes when searching in a query string for example without specific query implemenation in the mappers
guice optimization
only under debug logging use the source provider to find the line number through stack trace elements, otherwise, its very expensive
make utf8 bytes response not reuse thread local buffer
no need, optimized conversion to bytes anyhow, and when sending, it will just get wrapped by a buffer
automatically set translog buffer size based on number of shards
similar to how we set the indexing buffer size, automatically set the translog buffer size based on the number of shards allocated on a node
optimize reroute
- optimize initialization of building the all the assigned shards state
- optimize iteration in throttling allocation decider
Don't reset TokenStreams twice when highlighting.

When using PlainHighlighter, TokenStreams are resetted both before highlighting
and at the beginning of highlighting, causing issues with analyzers that read
in reset() such as PatternAnalyzer. This commit removes the call to reset which
was performed before passing the TokenStream to the highlighter.

Close #3200