Add GEC-only pass through line to Hlt1

This line is needed for the physics performance comparison between Allen and Moore, where I would like to evaluate the GEC-only efficiency of Moore and be able to plot the decisions across kinematic space using the HltEfficiencyChecker tool. The simplest way to do this was to add a line that only filters based on the GEC. Such a line may also be useful in the future.

Needs !412 (merged) and is needed for MooreAnalysis!7 (merged).

I also add the SingleHighPtMuonLine to the list of comparison lines.

FYI @mvesteri @rmatev @thboettc @dovombru

Hlt/Hlt1Conf/python/Hlt1Conf/lines/gec_passthrough.py

+###############################################################################
+# (c) Copyright 2019 CERN for the benefit of the LHCb Collaboration           #
+#                                                                             #
+# This software is distributed under the terms of the GNU General Public      #
+# Licence version 3 (GPL Version 3), copied verbatim in the file "COPYING".   #
+#                                                                             #
+# In applying this licence, CERN does not waive the privileges and immunities #
+# granted to it by virtue of its status as an Intergovernmental Organization  #
+# or submit itself to any jurisdiction.                                       #
+###############################################################################
+from __future__ import absolute_import, division, print_function
+from PyConf import configurable
+from Moore.config import HltLine
+from RecoConf.hlt1_tracking import require_gec
+
+
+@configurable
+def gec_prefilters():
+    return [require_gec()]
+
+
+@configurable
+def gec_passthrough_line(name='Hlt1GECPassThroughLine', prescale=1):
+    """A line that returns a positive decision if the global event cut passes.
+
+    Can be useful for determining the GEC efficiency of a given physics
+    process when run over simulated data.
+    """
+    return HltLine(name=name, algs=gec_prefilters(), prescale=prescale)