Add a mechanism to reset all flops of a `Sequential`

[mkorbel1]

Motivation

"It's cumbersome and error prone to have to keep resetting flops I'm adding"

When creating lots of flops in a Sequential, often you want them all reset by the same reset signal. It would be convenient to make that an option.

Desired solution

An option in Sequential or a new type of sequential object that handles reset across all flops it creates.

Alternatives considered

Currently, each flop must be manually reset.