[features] improvement of session and window-placement
- allow pinning of windows using title-bar context-menu to make them sticky on their window/workspace position until unpinned. This should also be saved after closing the program and restoring it exactly there next time.
- integrate some kind of session-manager which is able to save window positions and restore them when launched or optionally even after new login asking to restore the previous user-session (like macos does).