Island: Change schema compiler to merge plugins and exploiters

[VakarisZ]

What does this PR do?

Exploiter plugins and hard-coded plugins must be merged to create a cohesive configuration schema

Fixes part of #2785

PR Checklist

• Have you added an explanation of what your changes do and why you'd like to include them?
• Is the TravisCI build passing?
• Was the CHANGELOG.md updated to reflect the changes?
• Was the documentation framework updated to reflect the changes?
• Have you checked that you haven't introduced any duplicate code?

Testing Checklist

• Added relevant unit tests?
• Have you successfully tested your changes locally? Elaborate:

  Tested by running unit tests

• If applicable, add screenshots or log transcripts of the feature working

[VakarisZ]

This is the wrong description, will fix in later PR

[mssalvatore]

Approved, but I think we can improve a few names.

[mssalvatore]

Suggested change

	def _add_exploiters(self, schema: Dict[str, Any]) -> Dict[str, Any]:
	def _add_non_plugin_exploiters(self, schema: Dict[str, Any]) -> Dict[str, Any]:

[mssalvatore]

Suggested change

	def _add_properties_to_objects(self, schema: Dict[str, Any]) -> Dict[str, Any]:
	def _add_properties_field_to_plugin_types(self, schema: Dict[str, Any]) -> Dict[str, Any]:

^^ Not sure about this name, but something more descriptive would be good.