Refactor Flank repo to single setting.gradle

[jan-goral]

Author the user story for this feature

As a developer, I want to work on a single Gradle project with multiple modules instead of multiple projects so I can edit and build everything in a single IDE instance.

Is your feature request related to a problem? Please describe.
I'm always frustrated when I need to open a new instance of IDE or switch to another when I want to edit a different project from flank repository.

Describe the solution you'd like
All Gradle projects from the Flank's repository should be converted to Gradle modules and included in a single setting.gradle.kt

Additional context
This issue may impact have an impact on #1095 and #1109