Adds SystemEntity Annotated Caches

[kingzacko1]

Description

• Adds support for @SystemEntity annotated caches.
• Adds a forceUpdate method in ScopedEntityMongoUtils for usage in migrations

/prd Graylog2/graylog-plugin-enterprise#9557
/nocl see related enterprise PR for CL entry

Motivation and Context

Required in support of Graylog2/graylog-plugin-enterprise#9557

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Refactoring (non-breaking change)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.