feat: Initial implementation of adding nodes to favorites

[Kealper]

Initial implementation of support for favorite nodes. Adds support for and closes #1011

I've tested this in the simulator while it was connected to a real node and it seems to work as you'd expect, but it'll need a second pair of eyes on it because I'm not familiar with Kotlin and this is my first time working with it.

[andrekir]

Thanks for your contribution! We're in the process of moving some of the NodeMenu items to the node details screen, as it is getting too crowded. Once #1517 is merged we'll revisit this.

[Robert-0410]

Nice one.

[Kealper]

Thanks for your contribution! We're in the process of moving some of the NodeMenu items to the node details screen, as it is getting too crowded. Once #1517 is merged we'll revisit this.

Sounds good! Once that commit is in, I'll migrate this to the new spot.

[jamesarich]

Looks great for a Android/Kotlin first-timer! Thanks for dipping your toes in, always happy to have more help.