tweak the expected output from serialising an empty component; add some tests for setting, getting, and unsetting valid and invalid component names
tweak the expected output from serialising an empty component; add some tests for setting, getting, and unsetting valid and invalid component names

MichaelClerx/libcellml,libcellml/buildbot-testing,nickerso/libcellml,cellml/libcellml,hsorby/libcellml,cellml/libcellml,MichaelClerx/libcellml,cellml/libcellml,hsorby/libcellml,nickerso/libcellml,MichaelClerx/libcellml,hsorby/libcellml,nickerso/libcellml,hsorby/libcellml,cellml/libcellml,nickerso/libcellml,libcellml/buildbot-testing