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 42.49%. Comparing base (c93bf3c) to head (0d44187).

Files with missing lines	Patch %	Lines
src/app/components/elements/panels/UserProfile.tsx	39.13%	14 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 ⚠️
.../components/navigation/EmailVerificationBanner.tsx	85.71%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1947      +/-   ##
==========================================
+ Coverage   42.46%   42.49%   +0.03%     
==========================================
  Files         575      575              
  Lines       24521    24533      +12     
  Branches     7227     7235       +8     
==========================================
+ Hits        10413    10426      +13     
+ Misses      14062    14061       -1     
  Partials       46       46              

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