Moved model down to instance level

What does this MR do?

This MR removes all unnecessary props from the core Editor Lite. model prop has been moved to the instance level to allow for multi-instance editor. Other props have been either completely removed or turned into configuration parameters for instance without providing those in the public API of the instance.

NOTE: The change is just a ~"feature::maintenance" refactoring, hence no changelog entry has been provided.

Screenshots

No visual changes.

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

References #241023 (closed)