Fix Ctrl+C and tests on Windows. (#1808)

* Fix Ctrl+C on Windows.

* Disable testing of a function N/A on Windows.

* Add test for coverage, avoid crash on missing _stopping.

* Initialise StreamingHTTPResponse.protocol = None

* Improved comments.

* Reduce amount of data in test_request_stream to avoid failures on Windows.

* The Windows test doesn't work on Windows :(

* Use port numbers more likely to be free than 8000.

* Disable the other signal tests on Windows as well.

* Windows doesn't properly support SO_REUSEADDR, so that's disabled in Python, and thus rebinding fails. For successful testing, reuse port instead.

* app.run argument handling: added server kwargs (alike create_server), added warning on extra kwargs, made auto_reload explicit argument. Another go at Windows tests

* Revert "app.run argument handling: added server kwargs (alike create_server), added warning on extra kwargs, made auto_reload explicit argument. Another go at Windows tests"

This reverts commit dc5d682448.

* Use random test server port on most tests. Should avoid port/addr reuse issues.

* Another test to random port instead of 8000.

* Fix deprecation warnings about missing name on Sanic() in tests.

* Linter and typing

* Increase test coverage

* Rewrite test for ctrlc_windows_workaround

* py36 compat

* py36 compat

* py36 compat

* Don't rely on loop internals but add a stopping flag to app.

* App may be restarted.

* py36 compat

* Linter

* Add a constant for OS checking.

Co-authored-by: L. Kärkkäinen <tronic@users.noreply.github.com>

tests/test_test_client_port.py

@@ -27,7 +27,8 @@ def test_test_client_port_default(app):
         return json(request.transport.get_extra_info("sockname")[1])
 
     test_client = SanicTestClient(app)
-    assert test_client.port == PORT
+    assert test_client.port == PORT  # Can be None before request
 
     request, response = test_client.get("/get")
-    assert response.json == PORT
+    assert test_client.port > 0
+    assert response.json == test_client.port