* fix(oidc): return bad request for base64 errors
We've recently noticed an increased amount of 500: internal server error status returns on zitadel cloud.
The source of these errors appear to be erroneous input in fields that are supposed to be bas64 formatted.
```
time=2024-04-08T14:05:47.600Z level=ERROR msg="request error" oidc_error.parent="ID=OIDC-AhX2u Message=Errors.Internal Parent=(illegal base64 data at input byte 8)" oidc_error.description=Errors.Internal oidc_error.type=server_error status_code=500
```
Within the possible code paths of the token endpoint there are a couple of uses of base64.Encoding.DecodeString of which a returned error was not properly wrapped, but returned as-is.
This causes the oidc error handler to return a 500 with the `OIDC-AhX2u` ID.
We were not able to pinpoint the exact errors that are happening to any one call of `DecodeString`.
This fix wraps all errors from `DecodeString` so that proper 400: bad request is returned with information about the error. Each wrapper now has an unique error ID, so that logs will contain the source of the error as well.
This bug was reported internally by the ops team.
* catch op.ErrInvalidRefreshToken
* define roles and permissions
* support system user memberships
* don't limit system users
* cleanup permissions
* restrict memberships to aggregates
* default to SYSTEM_OWNER
* update unit tests
* test: system user token test (#6778)
* update unit tests
* refactor: make authz testable
* move session constants
* cleanup
* comment
* comment
* decode member type string to enum (#6780)
* decode member type string to enum
* handle all membership types
* decode enums where necessary
* decode member type in steps config
* update system api docs
* add technical advisory
* tweak docs a bit
* comment in comment
* lint
* extract token from Bearer header prefix
* review changes
* fix tests
* fix: add fix for activityhandler
* add isSystemUser
* remove IsSystemUser from activity info
* fix: add fix for activityhandler
---------
Co-authored-by: Stefan Benz <stefan@caos.ch>
