Expanding the Core Library's Terminal Capabilities

[qxuken]

I want to expand the core:terminal library with basic building blocks for building TUI applications.

Proposed Additions:

1. Add some well-established ANSI sequences, like mouse tracking, alternate screen buffer management, and synchronized updates.
2. Introduce helper procedures to wrap common operations like coloring strings, clearing the screen, etc.
3. Add a cross-platform procedure to get the current dimensions of the terminal window, and update the core:sys/unix library to support ioctl and TIOCGWINSZ.
4. Add a procedure to enable and disable terminal raw mode, which is essential for TUI applications.
5. Create a cross-platform system for polling and parsing raw input into structured events for key presses, mouse actions, and terminal resizing.