backup: enable FastRestore metamorphic on remaining disabled tests

This is a tracking issue for turning on the `FastRestore` metamorphic in the remaining tests which have it disabled. The disabled tests fall into the following categories:

**Test Infra**:
There are a handful of tests which require refactors to work with the metamorphic, they generally fall into the following categories:
- Tests which validate the output of the RESTORE statement itself
- Tests which rely on setting ExternalIODir and reading files manually
- datadriven tests

**Feature Level**:
Tests which validate features that we currently do not have implemented for OR are disabled. This is primarily OR of encrypted backups, as well as tests which validate more complex tenant scenarios.

The tenant tests may be able to be turned on with a more heavy weight adjustment to the test infra structuring itself, but these are likely worth revisiting more holistically as we turn our attention to making OR work well in a multitenant setting.

Jira issue: CRDB-62551

Epic CRDB-62671