VectorDataWidget : Fix treatment of tooltips parameter
VectorDataWidget : Fix treatment of tooltips parameter

Despite the name, this is expected to match the length of the `data` and `header` arguments, according to usage in CompoundVectorDataParameterValueWidget and common sense.

andrewkaufman/gaffer,GafferHQ/gaffer,johnhaddon/gaffer,johnhaddon/gaffer,johnhaddon/gaffer,andrewkaufman/gaffer,johnhaddon/gaffer,ImageEngine/gaffer,lucienfostier/gaffer,hradec/gaffer,andrewkaufman/gaffer,hradec/gaffer,lucienfostier/gaffer,hradec/gaffer,appleseedhq/gaffer,andrewkaufman/gaffer,ImageEngine/gaffer,appleseedhq/gaffer,ImageEngine/gaffer,hradec/gaffer,lucienfostier/gaffer,hradec/gaffer,ImageEngine/gaffer,boberfly/gaffer,appleseedhq/gaffer,GafferHQ/gaffer,boberfly/gaffer,GafferHQ/gaffer,johnhaddon/gaffer,boberfly/gaffer,GafferHQ/gaffer,andrewkaufman/gaffer,appleseedhq/gaffer,GafferHQ/gaffer,boberfly/gaffer,lucienfostier/gaffer