Reimplement the DevEnv Settings Window with Textual.

[janosmurai]

Type Of Change

• New feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Any modification in the test cases
• Any modification in the documentation

Checklist:

• I have read and followed the contribution guideline.
• I have checked to ensure there aren't other open Pull Requests for the same update/change.
• I have made corresponding changes to the documentation.

Related Issue

Closing:
DEM-267
#199

Description

The DevEnv Settings Window got reimplemented in Textual. This change was needed, because the self-made TUI elements took to much time to change/update. The DevEnv Settings Window is now complex enough to introduce a TUI library.

How Has This Been Tested?

Tested on Ubuntu 22.04, with Alacritty terminal. I tried different sizes. I tested with both commands that leads to the DevEnv Settings Window: create and modify.

Screenshots (if appropriate):