refactor: fix some admin page modals, titles and content visual glitches

[lorenzo-cavazzi]

Some visual updates to the admin page to prevent modal overflow and use the current colors and titles

Before

After

Before

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/deploy

[RenkuBot]

You can access the deployment of this PR at https://renku-ci-ui-3894.dev.renku.ch

[leafty]

Not changed here, but this could be fixed:

[lorenzo-cavazzi]

Not changed here, but this could be fixed:

Somehow the vertical gutter "gy-3" on the row inside the container is messing up with the top margin 🤔
I fixed it here 664cf8b -- the solution is not the most elegant (I force the column margin to 0 and add it to the container element) but it works 🤷

[leafty]

OK 👍

Note: I think the collapse body left margin should be removed in this case. ms-1 works for this case:

In the screenshot, the collapse section is a sub-section of the Code Repository field.

Here the advanced section is a whole section on its own.

[leafty]

I have to say I do not like this conditional styling logic, it will be weird for the caller. I would rather remove the ms-1 and ps-2 props and let the caller set them.

[RenkuBot]

Tearing down the temporary RenkuLab deplyoment for this PR.