Creating signals for Map, Set, Iterable, List

[rodydavis]

Instead of:

final s = signal<List<String>>(['a', 'b', 'c']);

Could become:

final s = <String>['a', 'b', 'c'].toSignal();

This applies to Map, Set, List and Iterable and implements all the public methods and type for each.

[rodydavis]

Right now if a computer references a ListSignal there needs to be an explicit toList called to trigger rebuild

[rodydavis]

Curious if others have thoughts on this! Will merge if no major issues raised

[Kypsis]

These changes are definitely more ergonomic to use and have better self-documenting properties 👍