refactor(nextcloud_test,nextcloud): run tests on web

[Leptopoda]

Web tests are still a bit flaky when run together, and I didn't set up the test yet (my bash skills are terrible). Some initial feedback is appreciated, as I don't expect much to change.

To test it yourself:

• build the server dart run dart_frog_cli:dart_frog build (in the nc_test_api package)
• run the server dart run packages/nextcloud_test_api/build/bin/server.dart (in the nc package)
• run the tests dart test

As mentioned above, vm tests are fine, and all tests pass fine when run individually.

[Leptopoda]

I also have a branch using a hybrid test, but that requires spawning a separate docker container for every test case.

[provokateurin]

Doesn't need to be on any milestone since it only affects tests