Removal of Kuksa Example TLS certificates and Kuksa Server Tokens

[erikbosch]

As of today we have a submodule reference to kuksa.val repo to get Kuksa Server Tokens and Databroker Proto files. No Datarbroker has been moved to new repo, but Kuksa Server Tokens are still only in old repo as Kuksa Server is deprecated and will reach end of life at end of year.

By design we do not have example tokens for Databroker attached to kuksa-python-sdk. It would be good to get rid of the KUKSA Server (kuksa.val) dependency, but keep VISS support. We could also possible remove example TLS certificates

I would like to get feedback on:

• Is it OK now to remove KUKSA Server JWT tokens? It could create backward compatibility problems for users using KUKSA Server (but not Databroker) and relying on default tokens. Work-around is to install/download the tokens manually and refer to them
• Shall we at the same time remove the default TLS-certs/keys? That would affect also Databroker users relying on the default keys. Similar work around as above.

@SebastianSchildt - what is your opinion?

[erikbosch]

Will be fixed by #23