security: require verified email to accept invite when logged in

[mdtro]

See #64707

Users do not expect to be able to accept an invite with an email that does not align to the original invite's target email when they are already logged in. This PR changes the current behavior to only accept the invite if the logged in account has the email as an existing verified email.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.32%. Comparing base (b898450) to head (e4d3d68).

❗ Current head e4d3d68 differs from pull request most recent head b0494ad. Consider uploading reports for the commit b0494ad to get more accurate results

Additional details and impacted files

@@             Coverage Diff             @@
##           master   #66849       +/-   ##
===========================================
+ Coverage   48.69%   84.32%   +35.63%     
===========================================
  Files        6455     5306     -1149     
  Lines      287155   237136    -50019     
  Branches    49482    41016     -8466     
===========================================
+ Hits       139823   199966    +60143     
+ Misses     146786    36952   -109834     
+ Partials      546      218      -328     

Files	Coverage Δ
...sentry/api/endpoints/accept_organization_invite.py	97.97% <100.00%> (+66.40%)	⬆️
src/sentry/api/invite_helper.py	95.52% <ø> (+60.44%)	⬆️

... and 5538 files with indirect coverage changes

[getsantry]

This pull request has gone three weeks without activity. In another week, I will close it.

But! If you comment or otherwise update it, I will reset the clock, and if you add the label WIP, I will leave it alone unless WIP is removed ... forever!

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"A weed is but an unloved flower." ― Ella Wheeler Wilcox 🥀