Support Pixel Coordinates in Mouse Events

[bbb651]

Is your feature request related to a problem? Please describe.
Some terminals offer the ability to report pixel coordinates of mouse events along with the character coordinate. I want to make a UI based on the kitty image protocol (also blocked by #834) where pixel coordinates of events are important.

Describe the solution you'd like
I would like crossterm to provide access to these modes and add the pixel coordinates to MouseEvent.

Describe alternatives you've considered if any

Additional context
I found this website describing the SGR-Pixels (1016) mode.

[bbb651]

I just realized Event::Resize is also missing pixel sizes (there's a variety of xterm sequences for that, also there's TIOCGWINSZ with the ioctl syscall and SIGWINCH signal on unix). Are these not implemented due platform support? Also is this library for/against implementing image protocols such as the kitty image protocol, iTerm image protocol, sixel, etc? (they are relatively niche in terms of usage and platform support, and are relatively complex and require a cargo feature to avoid image crate dependencies, but I feel like there's a gap in the rust ecosystem for high level terminal image handling).