Django4 compatibility fix

[Tom-TBT]

This PR add fixes for Django 4 compatibility:

• changed- to _ for the app label in apps.py
• changed django.conf.urls.url to django.urls.re_path in urls.py

[vdegrandpre]

Hi, @strambc, who can approve this? I was going to create a pull request for the same issue. On recent versions of python environments, omero-web won't start without this fix in micrometaapp omero plugin. All the best.

[strambc]

Dear @vdegrandpre
thank you for your message.
We would be happy to approve @Tom-TBT's pull request but as you might have gathered this project is not actively developed and therefore we would prefer to have a conversation to explain the situation before moving forward.
If this makes sense I will reach out via email to organize a Zoom call