feat(feedback): add project option for enabling crash/user report notifs

[JoshFerge]

• add new epoch, epoch 12
• create new project option sentry:feedback_user_report_notification, and default it to True in epoch 12.
• add to project model / serializer

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (5f27fa1) 83.34% compared to head (979acf1) 84.16%.
Report is 4 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #65352      +/-   ##
==========================================
+ Coverage   83.34%   84.16%   +0.81%     
==========================================
  Files        5266     5266              
  Lines      235483   235494      +11     
  Branches    40768    40769       +1     
==========================================
+ Hits       196271   198208    +1937     
+ Misses      38993    37067    -1926     
  Partials      219      219              

Files	Coverage Δ
src/sentry/api/endpoints/project_details.py	88.11% <100.00%> (+0.04%)	⬆️
src/sentry/api/serializers/models/project.py	98.30% <ø> (ø)
src/sentry/models/options/project_option.py	100.00% <ø> (ø)
src/sentry/projectoptions/defaults.py	100.00% <100.00%> (ø)

... and 219 files with indirect coverage changes

[JoshFerge]

context:

Plan for Alerting on feedbacks from old user report API / crash report embed form:

• Right now we simply filter out "User Reports" (ones from crash report embed, and user report API), when we go to make notifications from feedbacks
• There are too many orgs who use these in ways where it doesn't make sense for them to go into the default alert notification (e.g. they have it set up to answer true/false yes/no questions)
• We'll make this a project setting, and have it on for new projects, and off for existing projects
  • For older orgs, they can go in and toggle this setting
  • Will update Alert rule should include a condition when a user submits issue via user feedback dialogue #5055 with instructions
    -Will talk to issues team about potentially using feedbacks as a signal for issue priority.