tag with @AwaitsFix because it causes the test suite to crash

see #3694
Also, this might have caused one of the problems described in issue #3674
Briefly delete manifested mapping type on a node without reason
When a dynamic type is introduced during indexing, the node that introduces it sends the fact that its added to the master, to be added to the master node. The master node then adds it to the index metadata and republishes that fact.

In order not to delete the mapping while the new type is introduced on the node that introduced it, we keep a map of seen mappings, and remove a mapping type when we already processed it.

The map is not properly cleared though in all places where an actual index service is being removed on a node.

closes #3697
update plugin
use static TL for common numeric precision values
Add dedicated Suggest Thread Pool
Add a dedicated suggest thread pool for the suggest API. With the new completion suggest type, which is purely CPU bounded, it makes more sense to have a dedicated thread pool for suggest compared to having it share the search thread pool and "competing" against other search operations.
closes #3698