Fixes to lines for strange decays

Several modifications on the lines to study strange decays are included, following the developments of !1605 (merged). These changes aim at implementing some of the fixes discussed in #585 and #597 (closed). These include:

• Getting rid of the requirements in the ghost-probability
• Using a regular combiner for dielectrons to avoid the zero-efficiency issues observed when using FunctionalDiElectronMaker
• Switch to standard selections in standard_particles.py (specially for neutral objects)
• Simplify the propagation of PVs
• Fix the monitoring histograms for lines whose input comes from particle filters (see #597 (closed))
• Inclusion of some downstream lines, in particular for for \Delta S = 2 hyperon decay modes
• Add isolation information to the head of all the decays (including intermediate particles)
• Include the VELO pixel raw-banks for modes where the head of the decay is a charged particle (in case we want to do offline studies matching the head of the decays to VELO tracks)
• Include the CALO raw banks for modes with neutral particles to allow for offline calibration
• Include the muon raw banks for modes with muons to allow for offline calibration and the possible development of a dedicated mun-identification algorithm (as in Run 2)

Efficiencies (6a1bd8d0)

Decay	Efficiency (this/master, %)
K_S^0 \rightarrow \mu^+\mu^-	20.9/17.5
K_S^0 \rightarrow e^+e^-	5.0/4.5
K_S^0 \rightarrow \mu^+\mu^-\mu^+\mu^-	12.0/7.5
K_S^0 \rightarrow \mu^+\mu^-e^+e^-	7.5/4.7
K_S^0 \rightarrow e^+e^-e^+e^-	0.0/2.5
K_S^0 \rightarrow \pi^+\pi^-e^+e^-	3.3/1.1

Efficiencies are computed with respect to CanRecoChildren.

Rate and throughput

Rates can be found in rates.jon. The following numbers correspond to the lines under Hlt2Conf.lines.rd.strange.

	This MR	Master
Rate	0.5~\text{kHz}	1.5~\text{kHz}
Total throughput	0.01~\text{GB/s}	0.02~\text{GB/s}
Average event size per event	1.9\times10^{-5}~\text{GB}	1.3\times10^{-5}~\text{GB}
Number of lines	62	51
Average throughput per line	0.17~\text{MB/s}	0.39~\text{MB/s}

The rates and bandwidths have been computed with HltEfficiencyChecker running over 168104 events (81 passed the selections).