Backend: implement list function

[fersaru]

Implements a list command with note.js as the template.

Things that still needs to be addressed are:

• some sort of interface for reporting errors to the frontend
• finding a fitting place for error logs without disturbing the user but having a opportunity to get more information about an error
• tests in rust for the backend only

[falk-werner]

In order to test this, we might want to provide a test directory. Than we can prepare a test directory of some structure and how our implementation react. We also might want to configure the directory later. In note.py and note.js, yaml configuration files are used. We don't need to introduce yaml configuration here (but we can, if you want to), but we should at least provide some directory to the implementation for test automation.

[fersaru]

In order to test this, we might want to provide a test directory. Than we can prepare a test directory of some structure and how our implementation react. [..] but we should at least provide some directory to the implementation for test automation.

I was thinking: maybe actual files are not needed. I want to check how deep I can mock things. But if I can't mock as early as I want, I think for test purposes, generating a test directory with content and deleting it after a test would be the best.

We also might want to configure the directory later. In note.py and note.js, yaml configuration files are used. We don't need to introduce yaml configuration here (but we can, if you want to),

A configuration for the storage location must be possible. Currently there is no menu to do so. A file for storing this information permanently is vital. Yaml, Json or toml syntax shouldn't be a problem since rust has crates for everything.

[falk-werner]

Currently there is no menu to do so

In note.py and note we only had config files without any in-app configuration. Here, we already have a settings menu. Take a look at the extra buttons on our title bar. There is only one option there by now and I don't know if it's worth to keep this particular option, but we can add more options there.