ServerMethods: Remove unneeded variables

Change-Id: I8e6332d193873dac23fdcabd6767d3e9ee09a4a7
ServerMethods: Use constants for "type" literal strings

Change-Id: I3c217659407922d873db47b4223e9e59b294a0d4
ServerMethods: Return sessionId on all correct requests

Change-Id: I160c3e8b592345d1301a4324d9b3c2a0b92bbdae
CMakeLists.txt: Disable log on tests by default

Change-Id: I9bc402b2f29945e7ad54ce385cff5894fd952352