ALZ Sync - Add the capability to define more fields in the policy assignments

[cjtous1]

Is your feature request related to a problem? Please describe.
It would be nice if we could define more things than the default parameters for ALZ policies.
For example, I might want to tweak the non-compliance message from the default one provided by ALZ policies.
Or maybe I want to add a resource selector or an override...

Describe the solution you'd like
The solution would allow me to be define more fields than just the parameters in the policy assignments.
Ideally, all fields here: https://learn.microsoft.com/en-us/azure/governance/policy/concepts/assignment-structure
The ones I would like most would be:

• Resource selectors
• Overrides
• Non-compliance messages
• Enforcement mode
• Excluded scopes
• Add additional metadata fields

[anwather]

I'm going to check in the ALZ accelerators how much you can modify via the config, as mentioned the ALZ policies are prescriptive and opinionated and there shouldn't be too many changes to them in most deployed environments. Will also check with the rest of the team but if huge changes are required to an ALZ policy assignment outside of the basics that ALZ exposes it would be easier to just keep that policy assignment in a separate folder within the repo.