[ENH] part types

[nicolas-sitylb]

Hello QWAT team,

some official survey offices use more part types than those provided in the official QWAT data model, for example (here in french) :

whereas the actual QWAT data model only provides those values:

SELECT id, value_fr, value_en, value_ro FROM qwat_vl.part_type;

Therefore, the correspondence is complicated. This is especially true as there are no "unknown"-like values.

That's why I'm asking if it could be possible to integrate, at least the most common values in the official QWAT data model?

(It would also be convenient to use the default values 101, 102 and 103 (see: #378 ))

Thanks.

[ponceta]

Very good input, it would be nice to list elements not in this list and check whether they are not in some other class in QWAT.

I've added a delta to your PR.