- can't convert lambda-with-captures to a function pointer (Clang 9)
- instead, use a context property .. QmlViewStep already sets a
"config" property with the Config object, but WelcomeQ wants it
as another name as well.
- this avoids registering the Welcome object across all QML pages,
as well.
NOTE: needs to have the QML adjusted for this change.
- The name is just the module identifier, and now we
search for *m@i* and also *m* from that identifier,
the name becomes much less important -- and it
can be set from the config key *qmlFilename* as well.
- The config context object should be set earlier, otherwise
QML code will try binding to a non-existent config already
- Document that QMLViewStep::setConfigurationMap() parent implementation
should be called **last**, at the end of the subclass implementation.
