Rewards UI cleanup

[christianbaroni]

What changed (plus any additional context for devs)

• Memoizes the cards on the Rewards screen
• Cleans up the next drop time, now shows e.g. "Today 4:20 PM" instead of "Tuesday 4:20pm" if the drop is happening at 4:20 PM on the current day
• Trims trailing zeros from "Rainbow users have earned" amount
• Fixes the rainbow text gradient width in the "My Points" section in the case where the device uses a non-standard system font size
• Cleans up the pending transactions spinner in the tab bar
• Fixes a bug causing the SmoothPager wrapper views to partly block the tap region behind the sheet in the case where the SmoothPager page heights differ
• Removes default exports in main points components

Screen recordings / screenshots

What to test

[brunobar79]

LGTM!