* Optionally prevent deletion and mutation of "MutableListSetting" items
* Save server metadata per device
This makes it possible to e.g. have different settings on a desktop and a smartphone.
* Move "TextSetting" to new folder
* Extract dialog of "TextSetting"
* Immediately show dialog when adding a list item
* Reuse "TextSettingProps" for "MutableListSetting"
* Add "placeholder" prop to "MutableListSetting"
* Prevent duplicates by default
* Clear dialog values on save
* Validate repo url
