* [Buttons] Remove .largeIcon shape from FloatingButton (#2513)
The LargeIcon shape is not required, since the same behavior (support
for 36-point images) can be achieved by setting the contentEdgeInsets to
.zero.
Also updates one of the button examples to use a 36-point icon.
* [Buttons] Add extended FAB layout code (#2528)
Creating (internal for now) the required properties and layout code to support
the extended FAB. Unit tests to confirm the behavior and some minor
adjustments to existing values like default contentEdgeInsets values.
Implements #2495
* [Buttons] Expose Extended FAB properties (#2543)
Making the new properties public and also migrating away from simple
property setters to the new forShape:inMode: setters required for
UIAppearance support.
* minimumSize
* maximumSize
* contentEdgeInsets
* hitAreaInsets
Implements #2495
* [Buttons] Add basic Floating Button example (#2554)
Includes automatic adjustment of extended/normal layout depending on size
classes.
Demonstrates #2495
* [Buttons] Update README for Extended FAB (#2561)
The README includes usage examples for the FAB. Adding a section to
demonstrate how to configure the FAB in its different shapes and modes.
Documents #2495
