tests: fix and update tests: - update code to newer version of `sh` - update code to newer version of `selenium` - update names of OMEMO algorithms - fix paths and names used to mount source to the test container - skip modules using `Gst` and `PyQt` when they are not available.

this certificates are used to enable TLS during tests. Those must be the same as in
backend_e2e (they are generated there)