IMPACT: improve rupture conversion, both from ShakeMap fault rupture and from finite-fault model

[ptormene]

Supersedes https://github.com/gem/oq-engine/pull/10668

The workflow Use finite rupture from the USGS was replaced by two different options:

1. Use ShakeMap fault rupture from the USGS (similar to the one that was replaced, but using Anirudh's code to make it possible to convert a wider set of ruptures from the USGS json format)
2. Use finite-fault model from the USGS (using Anirudh's code to convert the rupture from the finite-fault model associated to the given usgs_id)

I also added a check to identify cases in which the input data indicate that the hypocenter coordinates are outside the surface of the rupture. In those cases a warning is logged and presented to the user in the WebUI, and the hypocenter is relocated to the center of the surface of the rupture.

I made a number of little fixes and refactoring, so perhaps it would be good to let the Risk team test this branch on the impact-staging machine before merging it into master.