Add new plugin edgescroll to automate panning of game/region maps

[NicksWorld]

This adds a new plugin that when enabled can automatically pan the game world and various region maps throughout the game.
The particular supported screens are:

• Fortress/Adventure Game World
• Worldgen Preview
• Embark (overview, and zoomed)
• World screen

In action:

2025-11-27.14-46-13.mp4

2025-11-27.14-46-56.mp4

[NicksWorld]

An edge case was found where some screen resolutions cause df to mark the precise_mouse_x/y as invalid when moved to the border. Mouse position will need read from SDL directly.

[NicksWorld]

In order to read the mouse position directly, dfhooks_sdl_loop is connected to a queue mechanism in DFSDL to queue callback methods to run on the renderer thread. This is done because many SDL methods, including those to get mouse position, need to run on the main thread. These methods are executed from dfhooks_sdl_loop and are cleared after execution.

For window-edge presence detection, real coordinates are used instead of logical coordinates as DF doesn't update the logical size of the renderer when the window is resized whilst in fullscreen (very possible with tiling window managers).