None of the paths in Identity/Server.pm check for method type

All of the paths in https://github.com/matrix-org/sytest/blob/develop/lib/SyTest/Identity/Server.pm just check the path of the request, not the method type.

Doing so may help root out some bugs in implementation.

Start by reading lib/SyTest/Identity/Server.pm and review every request path it handles. Update the checks so method type is considered alongside the path, then verify the Identity server tests or integration suite cover the relevant request methods and no longer accept incorrect ones.

Written by the indexing model from the issue text.