[macOS] Add Mouse special key(Back, Forward) on macOS by button number

[IRONAGE-Park]

Currently, macOS does not support input for mouse special keys.(Back, Forward)

To add this functionality, if the special input is of type OtherMouseUp / OtherMouseDown on macOS, send the mouse's number along with it so that special keystrokes can be supported.

This is a very simple way to do this.

Increase the number in last_moues_click by 2, from 7 to 9, since the total number of keys supported on macOS has increased.

It would be nice to specify that last_mouse_click should be incremented as the number of supported mouse keys increases, or to make it consistent via tests or types.
I realized later that the reason the test didn't pass in this fix was because of the "index out of bounds" of last_mouse_click

[pentamassiv]

Thank you for your PR! The code looks good and I only have a few minor suggestions.

It would also be nice to add it to our changelog (CHANGES.md), but I can also do that. The PR currently contains 5 commits. I'd prefer this to only be one commit. Please squash the commits, or I can do it when merging it.

[pentamassiv]

Great, thank you. I don't have a mac to test this on right now. Did you test it? If you use a browser and then simulate a press of the "Back" button, does the browser go to the previous page or what happens?

[IRONAGE-Park]

This is an example of using mouse clicks in a project that references enigo, which I forked.

Here's Cargo.toml.

[package]
name = "enigo-test"
version = "0.1.0"
edition = "2021"

[dependencies]
enigo = { git = "https://github.com/IRONAGE-Park/enigo.git", branch = "add/macos-mouse-special-keys" }

[pentamassiv]

Awesome, thank you so much!