Ensure to only clear current client cache when logging out

[frederikprijck]

Changes

When calling logout, we would call cacheManager.clear() without specifying any client id, resulting in clearing all data from the cache, including those belonging to other clientId's as the one configured in the current Auth0Client instance.

When using local storage, this results in logging out both app1.domain.com and app2.domain.com (both using a different clientId), when that might not be intended.

Unless the user sets clientId to null, we should only clear the data from the cache that belongs to either the provided clientId, or the globally configured clientId.

References

Fixes #1063

Testing

• This change adds unit test coverage
• This change adds integration test coverage
• This change has been tested on the latest version of the platform/language

Checklist

• I have read the Auth0 general contribution guidelines
• I have read the Auth0 Code of Conduct
• All code quality tools/guidelines have been run/followed