[Index Management] Edit index

[cjcenizal]

Overview

There are certain aspects of indices which can be changed without requiring a reindex. For example:

• As mentioned by @111andre111 in Reindex Wizard #46755 (comment), you can change the ignore_above parameter on keyword fields and coerce parameter on numeric fields in an index's mappings.
• New fields can be added to an index's mappings.
• ...more?

Editing an index will leverage the same wizard used by index creation (#57059). We'll need to update the UI to disable or hide any aspects of an index that can't be changed in-place.

Enhancements

ECS migration tools

Being able to edit an index will enable users to perform their own ECS migration (#26807) and will create a place for us to add tools to make this process easier.

[elasticmachine]

Pinging @elastic/es-ui (Team:Elasticsearch UI)

[cjcenizal]

Relates to the Reindex Wizard: #46755