[rset] Deprecate the 'encoded' argument to ResultSet.printable_rql() It's hardly used at all, and when used inside CubicWeb, it's only set as false. Better make sure that this function always returns a proper unicode string and let the caller handle conversion on its own.

[gcdebug] ignore _NeedAuthAccessMock instances When looping over gc.get_objects(), we'd crash in _NeedAuthAccessMock.__getattribute__.

[views] Fix 'gc' view to use 'repo_gc_stats' service