Color set unified & removing unnessacry vanilla bootstrap dependencie

Closes #1202 (closed) Closes #1044 (closed)

What does this MR do?

This request, adds the same color CSS variables to old and new CSS. The color variables can be adjusted via colors.scss. The bootstrap packages, which is not required, is removed.

Links and button should be now unified, in some special cases there is a bit of variance of font-sizes and paddings or margins. Mostly on the old CSS.

On some points, the colors are now a bit brighter, or less saturated. But this is based on the same color calculation which is used by bootstrap.

How confident are you it won't break things if deployed?

The Navigation is a bit off, but this will be fixed when Navigation 2.0 is coming in an upcoming MR. 🤷

This requires some follow-UP MR because it loads bootstrap globally and not on specific elements or pages. Maybe some input fields are scuffed.

Screenshots (if applicable)

before	AFTER

Styleguide

Checklist

• [?] added a test, or explain why one is not needed/possible...
• no unrelated changes
• asked someone for a code review
• set a "for:" label to indicate who will be affected by this change
• added to the next milestone (see https://gitlab.com/foodsharing-dev/foodsharing/-/milestones, unless it has a "for:Dev" label)
• added an entry to CHANGELOG.md
• added a short text that can be used in the release notes
• Once your MR has been merged, you are responsible to create a testing issue in the Beta Testing forum: https://foodsharing.de/?page=bezirk&bid=734&sub=forum. Please change the MRs label to "state:Beta testing".
  • Consider writing a detailed description in German.
  • Describe in a few sentences, what should be tested from a user perspective.
  • Also mention different settings (e.g. different browsers, roles, ...) how this change can be tested.
  • Be aware, that also non technical people should understand.

Release notes text in German

Die Farben der gesamten Webseite wurden angegelichen, betrifft hauptsächliche Links und Buttons.