feat: Support FAB tab page MD transitions

# Feature Request

**Ionic version:**
4.11.4

**Describe the Feature Request**
As of 4.11.4, there's no apparent way to follow the material design guidelines on how a FAB should animate when changing tabs, to give the impression that it's not multiple FABs but a single one.

**Describe Preferred Solution**
This is the transition according to MD:

It would be great to have this animation in Ionic. Even better if it's router/tab aware.

*Describe Alternatives**
A more simple solution would be to add this animation and offer a hook to control it.