Improve UI of creating configurations

[goerlibe]

Creating Configurations requires multiple user inputs. Currently they are collected using individual prompts. The vs code API allows to create proper multi-step inputs using QuickInputs.
We want to support the following features:

• allow going back and forth between steps.
• when specifying paths, the UI should provide suggestions based on the current input
• when specifying paths the UI should show an option to create directories/files
• we should properly recognize if the user aborted (e.g. pressed ESC) or continued without providing input.
• we may want to validate some of the inputs.
• reusable code is preferred.

Example of a pretty UI:
https://github.com/microsoft/vscode-extension-samples/blob/main/quickinput-sample/preview.gif

[goerlibe]

Since this can be done without understanding much of the rest of the code, I updated the description and added the good first issue tag. Maybe someone from the open source community wants to help out 😄