Incoherent behaviour in project folder settings

[BartChris]

Describe the bug
Adding or deleting folders in the project settings works different. When i add a folder, it is not necessary to save the new setting. It seems to be saved automatically. When i delete a folder, i have to explicitely save the settings in order for the settings to take effect.

Screen in question is this.

This especially becomes appearant when i delete a folder and want to add a new folder with the same filegroup. Although the old entry is no longer visible it still has effect on newly created folders.

To Reproduce
Steps to reproduce the behavior:

1. Create a new folder
2. Leave the project page without saving
3. Return to the project page - created folder is there
4. Delete a folder
5. Leave the page without saving
6. Return to the page, folder is not deleted

Expected behavior
The behaviour should be coherent. I suggest to only save the folders on an actual save. If a folder is deleted in the UI (although not saved) it should be possible to add a new folder with the same file group.

Kitodo 3.7, 3.8, Master