Add about dialog to dashboard

[jraddaoui]

• Update API generated code and client to include about service.
• Add info icon to the header to open a dialog with about information.
• Show information from the about API endpoint (version, pres. system, child workflow names), include the same text from the homepage and buttons to documentation, license and contributing.

Unrelated changes:

• Make sure padding is not added to the body when a dialog is shown.
• Bold "Enduro" in the header to match dialog.
• Update homepage text to match dialog.
• Redirect to signin page after API authentication error.

Refs #1062.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 54.82%. Comparing base (be6554c) to head (6ecb34b). Report is 1 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1082 +/- ## ========================================== + Coverage 54.69% 54.82% +0.12% ========================================== Files 105 105 Lines 7696 7696 ========================================== + Hits 4209 4219 +10 + Misses 3228 3221 -7 + Partials 259 256 -3 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[jraddaoui]

Work in progress:

Clicking on the top-right info icon will show that dialog. I still need to add some template and style to get closer to the wireframes from the issue. Moving the user menu to a drop-down including a link to the dialog will probably happen in another PR.