Enable pythia8 selective channel on/off

[nusense]

Implement method for matching PDGLibrary/TDatabasePDG channels to Pythia8 channels via FindPythiaDecayChannel(); give warnings if a match isn't found
Correct state flipping of onMode for turning "on" channels
Implement new virtual PrintDecayChannelInfo() method specific to Pythia8 case
Add to more comments to config/CommonDecay.xml regarding these changes

[LiangLiu212]

I tested it with tau(15) and D(411) and it works as expected. I'm going to approve this PR.

However, we have a issue with DIS event record.

|------------------------------------------------------------------------------------------------------------------|
|GENIE GHEP Event Record [print level:   3]                                                                        |
|------------------------------------------------------------------------------------------------------------------|
| Idx |          Name | Ist |        PDG |   Mother  | Daughter  |      Px |      Py |      Pz |       E |      m  |
|------------------------------------------------------------------------------------------------------------------|
|   0 |         nu_mu |   0 |         14 |  -1 |  -1 |   4 |   4 |   0.000 |   0.000 |  10.000 |  10.000 |   0.000 |
|   1 |          Ar40 |   0 | 1000180400 |  -1 |  -1 |   2 |   3 |   0.000 |   0.000 |   0.000 |  37.216 |  37.216 |
|   2 |       neutron |  11 |       2112 |   1 |  -1 |   5 |   5 |  -0.055 |   0.130 |   0.078 |   0.922 | **0.940 | M = 0.908
|   3 |          Ar39 |   2 | 1000180390 |   1 |  -1 |  16 |  16 |   0.055 |  -0.130 |  -0.078 |  36.294 | *36.286 | M = 36.293
|   4 |           mu- |   1 |         13 |   0 |  -1 |  -1 |  -1 |   1.106 |   0.778 |   3.387 |   3.648 |   0.106 | P = (-0.303,-0.213,-0.929)
|   5 |      HadrSyst |  12 | 2000000001 |   2 |  -1 |   6 |   7 |  -1.161 |  -0.648 |   6.691 |   7.274 | **0.000 | M = 2.524
|   6 |             u |  12 |          2 |   5 |  -1 |   8 |  11 |  -1.085 |  -0.605 |   6.250 |   6.381 |   0.330 |
|   7 |          ud_1 |  12 |       2103 |   5 |  -1 |  -1 |  -1 |  -0.076 |  -0.043 |   0.441 |   0.893 |   0.771 |
|   8 |           pi0 |  14 |        111 |   6 |   7 |  12 |  12 |  -0.259 |  -0.220 |   2.818 |   2.841 |   0.135 | FSI = 1
|   9 |       neutron |  14 |       2112 |   6 |   7 |  13 |  13 |  -0.216 |  -0.007 |   1.472 |   1.759 |   0.940 | FSI = 1
|  10 |           pi+ |  14 |        211 |   6 |   7 |  14 |  14 |  -0.306 |   0.214 |   1.093 |   1.163 |   0.140 | FSI = 1
|  11 |           pi0 |  14 |        111 |   6 |   7 |  15 |  15 |  -0.380 |  -0.635 |   1.308 |   1.509 |   0.135 | FSI = 1
|  12 |           pi0 |   1 |        111 |   8 |   7 |  -1 |  -1 |  -0.259 |  -0.220 |   2.818 |   2.841 |   0.135 |
|  13 |       neutron |   1 |       2112 |   9 |   7 |  -1 |  -1 |  -0.216 |  -0.007 |   1.472 |   1.759 |   0.940 |
|  14 |           pi+ |   1 |        211 |  10 |   7 |  -1 |  -1 |  -0.306 |   0.214 |   1.093 |   1.163 |   0.140 |
|  15 |           pi0 |   1 |        111 |  11 |   7 |  -1 |  -1 |  -0.380 |  -0.635 |   1.308 |   1.509 |   0.135 |
|  16 |      HadrBlob |  15 | 2000000002 |   3 |  -1 |  -1 |  -1 |   0.055 |  -0.130 |  -0.078 |  36.294 | **0.000 | M = 36.293
|------------------------------------------------------------------------------------------------------------------|

The second mother index of the diquark in the final state is 7. This may indicate an issue within the FSI code, specifically that the daughter particle directly replicates the state of its parent, as I discussed with Robert.

Best.

Liang Liu