[dashboard] Handle EE_LICENSE_REQUIRED

[AlexTugarev]

For Gitpod Self-Hosted installations the server component may return EE_LICENSE_REQUIRED error responses.

We need to implement a catch for these errors and also the page where to upload the EE license on.

[AlexTugarev]

@gtsiolis, this one would need to be redesigned 🙏🏻

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.