Revisit indices options and make default values consistent

[javanna]

We currently support different indices options within apis that execute against multiple indices: http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/multi-index.html .

We should revisit these indices options and defaults for each api and try to make them less confusing and more consistent.

Also, the code that applies these options, more specifically MetaData#concreteIndices, could use some love :)

[colings86]

+1

[clintongormley]

See #14102

[javanna]

One thing that recently came up is we should make a clearer distinction between internal options (e.g. forbidCloseIndices and ignoreAliases) and external ones (settable from REST e.g. ignore_unavailable, allow_no_indices and expand_wildcards). Unfortunately the internal ones are currently settable through java API while they should be unmodifiable (either one api can work against closed indices or it can not, it is a characteristics of the API itself).

Also, I would consider unifying allow_no_indices and ignore_unavailable, my head starts spinning anytime I have to remember what the subtle difference between the two is.

[elasticmachine]

Pinging @elastic/es-core-infra

[dakrone]

This has been open for quite a while, and hasn't had a lot of interest. For now I'm going to close this as something we aren't planning on implementing. We can re-open it later if needed.