Add project images

[waltersajtos]

Description

Project images were planned for a long time in the detail page, this pull request will implement both adding and showing the project images.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I updated the changelog with an end-user readable description
• I assigned this pull request to the correct project board to update the sprint board

Steps to Test or Reproduce

Outline the steps to test or reproduce the PR here.
These steps will be used during release testing.

1. Create a project with 2 project images
2. Go to the overview page and check if the images are shown properly
3. Edit the project and remove 1 image
4. Go to the overview page and check the other image is still there.
5. Edit the project and add another image
6. Go to the overview page and check if the new image is added.

Link to issue

Closes: #464
Closes: #539

[niraymak]

Thanks alot for another nice new feature Walter! 🥇

I had some remarks.

• For some reason when switching from homepage to project overview page it took like 9s to load all projects for me. Anyone else experienced this? (edit: after reboot it didn't happen anymore)

• I would suggest to replace the uploading image wizard page step to be after the upload project icon step.

• I like the new way of uploading a project icon in the edit page. But I think it may be a bit unclear how to delete it. I suggest we create a new issue for it if this would take too much time.

• On the edit project page a loading icon was permanently showing in the edit project button. I think this spinner is nicer than the one we use on other pages 👍
  

• Do you guys think we should give the carrousel buttons a different color? In this case they are not very visible.
  

• We could improve on how pictures are shown. For example this Delta icon isn't readable when uploaded. I guess we can create a new issue for that.
  

[liekevdvoort]

@niraymak i added a small dropshadow to combat the white background issue

Also i changed the carousel to stay in a 16:9 aspect ratio so the image looks the same on all devices

[RubenFricke]

Whenever I uploaded a project icon in the wizard and reopened the wizard, the project icon remained uploaded (partially). It says skip, but it shows an image as a preview. Is this expected?

[RubenFricke]

Thanks a lot! Looks good