Add feedback for why users cant vote

[pikachu0542]

What

Add alerts that tell the user why they are unable to vote. Specifically, this adds:

• An alert for if the user has already voted
• An alert for if the user is not active or didnt meet gatekeep
• An alert for if there was a database error

Why

When you cant vote in a poll, it just automatically redirects you to the results screen, without giving you any indicator of why you were sent to the results.

Test Plan

• Create a poll without gatekeep and verify you can vote on it
  • Either be an active member or set the dev force active flag to test this
• Create a poll with gatekeep and ensure you are allowed (either by meeting gatekeep or waived) and ensure you can vote
• Create a poll with gatekeep where you dont meet gatekeep, ensure you cant vote and an appropriate alert is shown and is closable
  • If needed, test this by adding return 4 as the first line of canVote func
• Ensure that you cannot vote in polls if you are not an active member and the appropriate alert displays and can be closed
  • Test this by putting return 3 as the first line of canVote function
• Vote in a poll, then go back to that poll and ensure that the alert saying you already voted appears and is closable
• Ensure that the appropriate alert appears and is closable if there is a database error
  • Simulate this by adding return 1 as the first line of canVote func

Env Vars

no changes

Checklist

• Tested all changes locally