[Console Monaco migration] Fix autocomplete suggestions for request body

[yuliacech]

After #182562 is merged, we need to fix following issues with the autocomplete suggestions for request body:

• Insert correct conditional template (for example, when creating a snapshot repo, the template is different depending on the type of the repo)
• Async suggestions (for example for fields) need to be correctly displayed after they are loaded from the backend
• The property values need to be correctly suggested (for example for property explain the autocomplete should show true and false)
• After inserting a template, we should ideally place the cursor in a position where the user would want to start typing. For example, when inserting an empty object as template {}, the cursor should be placed between curly brackets.

[elasticmachine]

Pinging @elastic/kibana-management (Team:Kibana Management)