Add Convert index to remote support for dashboard ism plugin

[wntmddus]

Description

Adds dashboard support for the new convert_index_to_remote action options.

This updates the visual policy editor to support:

• include_aliases
• ignore_index_settings
• number_of_replicas
• delete_original_index
• rename_pattern

Also updates the action model, default action config, sample policy fixture, and tests.

Notable behavior:

• number_of_replicas is optional. Leaving it empty omits the field so the restored remote index inherits the snapshot setting.
• rename_pattern defaults to $1_remote.
• rename_pattern must be non-empty and contain $1.
• number_of_replicas must be non-negative when specified.

[ztomaszewska]

hello @wntmddus I did not see this PR and created a new one (#1406) based on #1319 that was on hold for about 10 months. Of course there is no need for 2 PRs that are handing the same :) I can close mine as yours has more tests to it. However I can see you've added options that are not yet available in the ism backend plugin but you're missing rename_pattern that is now working.
It would be great if maintainers (maybe @saratvemulapalli ?) could pick up this topic of missing convert_index_to_remote action. Especially as we can see many people are willing to help to make it happen :)