✨NEW: rSCF to find material type

The user can currently specify two "Material settings":

* `SpinType` - Is the structure magnetic?
* `ElectronicType` - Is the structure a metal/insulator?

Although this is already fine, it would be a vast improvement if we could set these (either or both) to "Automatic", and simply run a reconnaissance SCF to figure out the setting automatically. This could simply be added to the work chain in case the user sets one of the two to "Automatic".

### Magnetism

Here we would use the rudimentary approach we have for our HT projects, as well as the one implemented in the protocol: Simply set the magnetic moments to the highest value based on which shell is partially occupied for that element (d -> 5; f -> 7). This will of course:

1. Only find ferromagnetic configurations.
2. Only find the high-spin configurations.
3. Non-magnetic materials might get stuck in local minimum and be labeled magnetic.

Hence, it might already be an improvement to fix [3] by also running the structure in a non-magnetic configuration. Pinging @mkotiuga. @flavianojs for comments.

### To be a metal or not to be a metal?

This can be checked immediately using the calculations for the magnetic configuration, by continuing with the configuration that has the lowest energy and checking:

* The smearing energy. If this is very low, the material is typically an insulator.
* The occupations. If the occupations are all close to being fully occupied or empty, the material is once again typically an insulator.

Pinging @lorisercole for comments. Also wanted to touch base with Tushar on this, but I don't know his GitHub handle?