Add ability to permanently hide email verification banner

[jacbn]

Adds an option in My Account to disable the email verification banner by adding a cookie. Explicitly warns that this is a bad idea.

Also fixes a minor UX problem in that, if you snoozed the banner, you couldn't request a new verification email until the banner came back. The warning in My Account is there for as long as you have not verified your account, and can only be removed by verifying.

[codecov]

Codecov Report

❌ Patch coverage is 37.73585% with 33 lines in your changes missing coverage. Please review.
✅ Project coverage is 43.71%. Comparing base (072c6a4) to head (26d05b2).

Files with missing lines	Patch %	Lines
src/app/components/elements/panels/UserProfile.tsx	37.50%	15 Missing ⚠️
.../components/handlers/InterstitialCookieHandler.tsx	16.66%	10 Missing ⚠️
src/app/state/slices/cookies.ts	25.00%	6 Missing ⚠️
src/app/components/content/IsaacVideo.tsx	0.00%	1 Missing ⚠️
...rc/app/components/navigation/DismissibleBanner.tsx	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1947      +/-   ##
==========================================
+ Coverage   43.68%   43.71%   +0.02%     
==========================================
  Files         594      594              
  Lines       25043    25056      +13     
  Branches     7425     8346     +921     
==========================================
+ Hits        10940    10953      +13     
+ Misses      14054    14047       -7     
- Partials       49       56       +7     

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