[feat] Resize adjacent windows together along a common window borders or corners in a window group

Related:
- #568

Example: https://www.nurgo-software.com/products/aquasnap#:~:text=Window%20tiling

Motivation: With support for dynamic grouping of windows along their shared borders or corners, it becomes natural to allow resizing all windows in the group by resizing that border or corner. This is a very useful feature that I miss from using AquaSnap on Windows, and for a long time was a major reason why I continued to use Windows.