always use urljoin

[ReimarBauer]

We have various places where + is used instead of urljoin
r = requests.get(self.mscolab_server_url + '/operations

That needs to become refactored

A side effect, when there is no Url, tests show this in python 3.11

tests/_test_msui/test_mscolab_admin_window.py::Test_MscolabAdminWindow::test_add_permissions
  /home/reimar/MASTER/MSS/conftest.py:222: UserWarning: An unhandled message box popped up during your test!
  PyQt5.QtWidgets.QMessageBox.critical(): [call(None, 'fatal error', 'Fatal error in MSS 8.2.0 on Linux-6.2.0-10018-tuxedo-x86_64-with-glibc2.35\nPython 3.11.4 | packaged by conda-forge | (main, Jun 10 2023, 18:08:17) [GCC 12.2.0]\n\nPlease report bugs in MSS to https://github.com/Open-MSS/MSS\n\nInformation about the fatal error:\n\nTraceback (most recent call last):\n  File "/home/reimar/MASTER/MSS/mslib/msui/mscolab.py", line 1395, in render_new_permission\n    r = requests.get(self.mscolab_server_url + \'/user\', data=data, timeout=(2, 10))\n                     ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~\nTypeError: unsupported operand type(s) for +: \'NoneType\' and \'str\'\n')]
    warnings.warn(f"An unhandled message box popped up during your test!\n{summary}")

[Myrausman]

Can you please assign this issue to me? Also, do I need to modify f'{mscolab_server_url}/test_authorized'?

[ReimarBauer]

Yes also the f' string syntax should use urljoin.
Later when we use os.path/fs.path join methods for files and urljoin for urls it becomes less error-prone.

It gets also much easier to collect all urls.