[FIX] Fix filter_events uri parameter order

[lrapp-adan]

The way the filter_events function calls pi_get (return self._s.pi_get(f'case/timeline/advanced-filter?q={filter_uri}&', cid=cid)) leads to the q parameter being placed before the cid parameter. One would not expect this to be a problem, but it is, as the API seems to expect the URI-parameters the other way around. This leads to the strange behavior of the API returning data from some other case id. (The last successfully accessed one? Maybe a caching problem / bug in iris-web? Unfortunately, I was not able to identify the root cause yet.)

However, this PR fixes the URI parameter order for the filter_events function to make it work for now.