This PR does those things:
- It allows API calls `MetaWrite` and `MetaRead` in maintenance mode.
- SystemInformation resource now waits for available META
- SystemInformation resource now overwrites UUID from META if there is an override
- META now supports "UUID override" and "unique token" keys
- ProvisionRequest now includes unique token and Talos version
For #7694
Signed-off-by: Dmitriy Matrenichev <dmitry.matrenichev@siderolabs.com>
