Today we allow to set all kinds of index level settings on the node level which
is error prone and difficult to get right in a consistent manner.
For instance if some analyzers are setup in a yaml config file some nodes might
not have these analyzers and then index creation fails.
Nevertheless, this change allows some selected settings to be specified on a node level
for instance:
* `index.codec` which is used in a hot/cold node architecture and it's value is really per node or per index
* `index.store.fs.fs_lock` which is also dependent on the filesystem a node uses
All other index level setting must be specified on the index level. For existing clusters the index must be closed
and all settings must be updated via the API on each of the indices.
Closes#16799
e91a141233