Error parsing $scope declaration where identifier contains double colons ::

[MBarae]

Similarly to issue #22 - pyvcd reader throws an error when parsing a $scope that has a double colons
Seeing this specifically with uvm scopes such as:
$scope task uvm_phase::m_wait_for_pred $end
Error:
vcd.reader.VCDParseError: 58:23: Expected $end