This adds generalized IncomingHttpMessage and OutgoingHttpMessage templates
that support different types of streams (via a std::variant) and can both
be used for either requests or responses.
The tacked on metadata from the old HttpRequest and server connection from
the old HttpServerConnection have been moved to HttpApi(Request|Response)
classes that derive from the above generalized message types.
It's annoying to have to wait 10 seconds for the `liveness_disconnect`
test to complete, so make the timeout configurable and set it to a way
lower value to test the functionality.
This adds a global fixture that can parse an additional argument to
the test executables (`--generate_ctest_config`). When run by
CMake during build, this generates a CTest script containing all
the tests and their properties.
An additional decorator, that defines CTest properties for a test case
or suite that will be added to the tests during config generation.
This version needs no hacks, no huge CMake scripts, just a bit of
additional C++ code that iterates over all test-cases and collects
the information CTest needs.
One caveat is still that this does not work with cross-compilation,
which probably isn't an issue to begin with, but there are also ways
to fix that if necessary.
