time remaining on proposals

[kylegrover]

use the proposal voting period, proposal waiting period, and proposal creation datetime to display the key datetimes and remaining time for each proposal.
I'm assuming these are also considered flexible dates as we can vote to change voting and waiting period during a proposals lifetime. if such a vote would change the end date of existing proposals then we might include a small note or 🛈 tooltip indicating such near the displayed dates and times