Filter out custom variables from Url

What does this MR do?

This filters out any possible custom variables that a user might send via the URL to the monitoring dashboard, interpolating in the queries that might use them.

Issue #214500 (closed)

Docs: !30725 (merged)

TODO:

• Add tests
• pass the variables to the network call that happens on the backend

Screenshots

N/A this only handles URL parameters and some network calls

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides