Add support for the Material Design 3 FAB Menu component

[voleum]

Material Design 3 introduces a new FAB menu component (https://m3.material.io/components/fab-menu).
This component provides a common MD3 pattern for exposing multiple primary actions, but it's currently missing in MDC.
I already have a working prototype based on the existing FAB — I’ve tweaked its behavior so it behaves more like the native MD3 FAB menu.
If you're interested in adding support for this component, I can refine my implementation if needed and open a PR.

FAB menu in Google Keep (reference)

My implementation in Aegis

[michaelschattgen]

Awesome, I like this! Thank you for opening an issue first. Definitely encourage opening a PR for this. What do you think @alexbakker?

[alexbakker]

Looks lovely! Sounds good to me.