feat(NumberInput): Implement NumberInput

Adds support for the number input component.

Has support for all props except:

input aria label since our text inputs don't have an aria label prop
onblur because I do not understand when this is supposed to blur and why it would
extra text input props because I was too lazy
keyboard buttons (seems like something that can be integrated well once the keyboard handling moves forward)

Quickstart PR coming up right away

patternfly-yew / patternfly-yew