fix(quart): Support quart_flask_patch

[sentrivana]

See #2709 (comment)

If quart_flask_patch is imported, it monkeypatches stuff so that the Quart app appears to be a Flask app. This confuses our Flask integration, which tries to enable itself and fails.

This PR:

• Makes the Flask integration detect that what it sees as Flask might actually be Quart.
• Reorganizes the Quart test suite a little to allow to test this case (a bit tricky since import quart_flask_patch needs to happen before anything else due to its monkeypatching nature).

Closes #2709

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.58%. Comparing base (4c9731b) to head (a48d978).
Report is 4 commits behind head on master.

✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4132      +/-   ##
==========================================
+ Coverage   79.48%   79.58%   +0.09%     
==========================================
  Files         140      140              
  Lines       15624    15630       +6     
  Branches     2651     2652       +1     
==========================================
+ Hits        12419    12439      +20     
+ Misses       2372     2358      -14     
  Partials      833      833              

Files with missing lines	Coverage Δ
sentry_sdk/integrations/flask.py	87.21% <100.00%> (+0.60%)	⬆️

... and 9 files with indirect coverage changes

[antonpirker]

Looks good.