difficult to reuse queries from QueryBrowser in the playground

[NicolasAnquetil]

The problem is that the "Current query code" tab was intended for creating queries in the queryBrowser, not in the playground:

• First, to apply the query, one needs a model, but it does not appear in the "Current query code" tab
• second, if the setting "Filter out stubs" is on, then this need to be added before the query
• this can be done with a simple reject: #isStub, but the queries expect a moose group, so it must be added too

and then there is moosetechnology/MooseIDE#1049