Refactor stepper input

[origami-z]

No site doc in this PR, will be in #3586

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• Refactored stepper input to not use Input component, which causes the props to be inconsistent (e.g. needing InputProps.inputProps)
• Added full border examples, supports theme next rounded corner styling options
• Updated increment / decrement button gap to be border-strong (suggested in #3878)
• Added more keyboard interactions, suggested by APG spinbutton, i.e., home/end, page up/down

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to do ..

• [x] rewrite changeset, API props change, & design change
• [x] add more test
• [x] add more visual snapshot, e.g., status, bordered, readonly, disabled

#1855, #3878