macOS Rust Library: Retrieve Coordinates of Focused Text Fields and Caret Positions

Develop a small Rust library tailored for macOS systems, enabling the extraction of crucial coordinates within text fields on any applications within macOS (global insertion coordinates). The library should have methods to effortlessly access the coordinates of actively focused text elements and the insertion point (caret) within them.

Key Requirements:

- The library should be compatible with macOS Sierra, High Sierra, Mojave, Sonoma, Ventura, and BigSur.
- Strict compatibility with Rust programming language.