Fix issue in ASGI header consumption

[TimPansino]

Overview

When an ASGIWebTransaction consumes the headers from a http.response.start event, it was doing so without regard to the allowable input types. When the headers are a generator, the generator was consumed by the call to process_response() leaving no headers remaining for the web server to send.

This exact same bug was also present in ASGIBrowserMiddleware, and requires the same fix.

• Fix this issue by consuming the generator into a list() object, preserving them. Then, pass this list to both process_response() and the web server.

Testing

Both bug fix commits are separated for ease of testing. Reverting the commit for either ASGIWebTransaction or ASGIBrowserMiddleware causes the included regression test to fail. This proves the issue can be caused by either wrapper and must be fixed in both.

[github-actions]

✅MegaLinter analysis: Success

Descriptor	Linter	Files	Fixed	Errors	Warnings	Elapsed time
✅ ACTION	actionlint	7		0	0	0.89s
✅ MARKDOWN	markdownlint	7	0	0	0	1.29s
✅ PYTHON	ruff	948	0	0	0	1.04s
✅ PYTHON	ruff-format	948	0	0	0	0.33s
✅ YAML	prettier	15	0	0	0	1.5s
✅ YAML	v8r	15		0	0	5.88s
✅ YAML	yamllint	15		0	0	0.7s

See detailed reports in MegaLinter artifacts

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 81.82%. Comparing base (f59f52c) to head (0c00bae).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1578   +/-   ##
=======================================
  Coverage   81.81%   81.82%           
=======================================
  Files         207      207           
  Lines       23965    23970    +5     
  Branches     3801     3803    +2     
=======================================
+ Hits        19608    19613    +5     
+ Misses       3090     3087    -3     
- Partials     1267     1270    +3     

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