Move closed polls to separate page

[pikachu0542]

What

Moved closed polls list to a separate page, and adds 2 links to the navbar:

1. Link to the poll creation page
2. Link to the closed polls page

Also made a new template for the navbar to reduce duplicated code.

Why

Having closed polls on a separate page makes it easier to access since you dont have to scroll past all the open polls.

Test Plan

• Ensure that all open polls are still shown on the home page
• Ensure the navbar has links to the poll creation and closed polls pages
  • Ensure the links on the navbar work properly
• Ensure all closed polls are shown on the closed polls page (not on the main page)

Env Vars

whats an env? (no)

Checklist

• Tested all changes locally

[BigSpaceships]

This is such a nitpick everything else looks great and W fixing things I say on slack, if you wanna dismiss the review and ignore the formatting stuff it could be another pr because it's probably not great in other places

but otherwise lgtm

[BigSpaceships]

Looks great!