Visualize API request progress

[ErikMichelson]

Which part of the project should be enhanced? UI dialogs where user input is processed by the backend.

Describe the solution you'd like Whenever an API request is performed after the user submitted something, show a spinner or similar loading icon to visualize that something is happening. This is especially important with slow (or mobile) internet where e.g. modals stay open for a few seconds after submitting data.

Describe alternatives you've considered Immediately close modals, do the request in the backend and inform the user about its success with a notification.

Additional context https://github.com/hedgedoc/react-client/pull/1636#discussion_r753799530

[DerMolly]

I like the idea and would like to suggest the HedgeDoc Logo with the animation of the circle of https://cssfx.netlify.app/

https://user-images.githubusercontent.com/3978662/145690346-f993d647-54a6-4f0f-9e58-157cf3aad8df.mp4

This could either be added as an overlay on top of the modal or alternatively it could replace the submit button.

[davidmehren]

Don't show the app logo when something is loading. That will cause the users to associate slowness with the app. Show a generic spinner instead.

[DerMolly]

This seems to be good advice