VariableNetworkNode: inconsistent behaviour of getName() and getQualifiedName()

[mhier]

VariableNetworkNode::getName() and VariableNetworkNode::getQualifiedName() return conceptionally different things depending on the type of the variable.

E.g. getName() gives for a variable "/mod/var":

• Application module: var
• Control system: /mod/var

And getQualifiedName() gives:

• Application module: /mod/var
• Control system: -> empty string

[mhier]

Now on redmine #8370