Revamping the Bottom Sheet widget

[TobiasHT5]

I think the bottom sheet widget needs a bit improvement from the current state that it is in.
First, for some reason the bottom sheet doesn't cover the whole width of the screen, I tried to
make it cover by using it's width attribute but it doesn't have one, so I tried increasing the width of the
content to page size but still couldn't fit the whole page.

Second, I think it would help if we had both the modal and standard bottom sheet like in the M3 spec.
We only have the modal one currently. Otherwise, everything else seems great, thank you.