Typed form groups

[enrique-lozano]

I'm submitting a

[ ] Bug / Regression
[x] Feature Request / Proposal

I'm using

NG Dynamic Forms Version: `X.Y.Z`

[ ] Basic UI
[ ] Bootstrap UI  
[ ] Foundation UI
[ ] Ionic UI
[ ] Kendo UI
[x] Material  
[ ] NG Bootstrap
[ ] Prime NG

Description

Currently the cretaeFormGroup method returns always an untyped form group. Will be nice to have some types there.