Added a view `long_ruptures`

[micheles]

The goal is to find the models in the mosaic affected by the problem of extra-long point ruptures probably due to a wrong width = src.lower_seismogenic_depth - src.upper_seismogenic_depth. The command to give is

$ oq run NAF/in/job.ini -p calculation_mode=preclassical,ps_grid_spacing=0,split_sources=false
$ oq show long_ruptures
| source_id | maxlen | usd | lsd     |
|-----------+--------+-----+---------|
| SC_51;0   | 958.9  | 0.0 | 45.0000 |
| BG_51     | 958.9  | 0.0 | 45.0000 |
| SC_51;1   | 1_451  | 0.0 | 45.0000 |

The complete list of tricky models is: ARB, AUS, CHN, MIE, NAF