PR #196081 adds support for surfacing deprecated APIs in the upgrade assistant.

We should surface the deprecated global saved objects HTTP APIs in Upgrade Assistant as an early warning of removal at a later stage. To show these warnings, deprecated has to change from a boolean to an object.
The warning will complement how the deprecations are logged.

We expect to update alternative APIs as they become available.

Deprecated Saved objects APIs

/api/saved_objects/{type}/{id}
/api/saved_objects/resolve/{type}/{id}
/api/saved_objects/{type}/{id?}
/api/saved_objects/{type}/{id}
/api/saved_objects/_find
/api/saved_objects/{type}/{id}
/api/saved_objects/_bulk_get
/api/saved_objects/_bulk_create
/api/saved_objects/_bulk_resolve
/api/saved_objects/_bulk_update
/api/saved_objects/_bulk_delete