Clean up the PV parsers

[redekok]

As a result of this issue I took a look at the modelling of our PV parsers. Currently, the app's VolatileParser handles PVPark and PVInstallation assets in the same way. Also, the RooftopPVParser doesn't seem to filter on ROOFTOP_PV as type of installation. Further, we've now implemented a quick and dirty fix for the situation in which no (SingleValue) profile has been specified, which should be replaced by a neater solution. Hence, I propose the following changes:

• Replace the configs for PVPark and PVInstallation by a generic PVPanel one. Since PVPanel is the parent of both PVPark and PVInstallation, this should work I think.
• Refactor the modelling of the RooftopPV parser: (1) filter for PVInstallationTypeEnum= ROOFTOP_PV and (2) provide a warning if no SolarPotential nor a production (in the form of a SingleValue profile) is given in the ESDL file.

Notifying @Charlottevm