Allow user to retry OAuth2/OIDC login

[fmoc]

I'm sure this could and should be polished. We are going to work on these widgets soon again when integrating them into the wizard, which is a good chance to improve the UX.

[TheOneRing]

Maybe we should move the icon to the top left? Especially when the error is displayed it looks like its not aligned to anything?

[fmoc]

WIP in an upcoming PR. This just adds the retry functionality.

[sonarcloud[bot]]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
3 Code Smells

0.0% Coverage
0.0% Duplication

[TheOneRing]

Sadly the change is so outdated that I can't take over the development...

[fmoc]

I was able to eliminate the hack due to some overall changes in the design of the dialog. Please review again.

[ownclouders]

Results for GUI-tests https://drone.owncloud.com/owncloud/client/13373/6/1

:boom: The GUI tests failed.

GUI Logs: https://cache.owncloud.com/public/owncloud/client/13373/guiReportUpload/index.html

Server Logs: https://cache.owncloud.com/public/owncloud/client/13373/guiReportUpload/serverlog.log

Screenshots:

• Delete_a_folder.png
• Filenames_that_are_rejected_by_the_server_are_reported.png

[fmoc]

Need to rebase this PR on https://github.com/owncloud/client/pull/10176, which fixes a couple of problems.

[fmoc]

Had to start over, but I managed to bring it into a usable state. Still investigating why the error label uses this much vertical space (Qt won't let me shrink it vertically during runtime at this point).

[sonarcloud[bot]]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
3 Code Smells

0.0% Coverage
0.0% Duplication