Resolve "Map follow-up"

What does this MR do?

• Improves map performance (especially for large numbers of markers)
• Added tooltips to markers (easily done with the new method of adding markers)
• Removed jittery display of map popup modals when opening them
• Fixed map popup modal loading animation (included data from previously opened object)

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

confident. If this solves the performance problems completely has to be tested in beta. On my PC it worked well with 60.000 stores.

Screenshots (if applicable)

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
• set the "API change" label if changes in the API are not backward compatible
• 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 in the release notes to /release-notes/YYYY-MM.md
• Once your MR has been merged, you are responsible to create a testing issue in the Beta Testing forum: https://foodsharing.de/region?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.

Closes #1940