Add support for DC gensets

[martinbosma]

In VenusOS v3.50~5 we added support for DC gensets. This is missing for gui-v2.

The related gui-v1 changes are these:

• Add dedicated page for gensets
• Add support for dcgenset service types
• PageGensetModel: add heatsink temperature (for Fischer Panda AGT)
• Add support for Hatz DC gensets
• Add support for Fischer Panda AGT gensets

The following changes are related, but might already be included:

• Genset: rename 'AutoStart' to 'RemoteStartModeEnabled'
• Refactored MbItemFpGensetError to MbItemGensetError
• ~PageGensetModel: use /Error/0/Id~ (will be done by https://github.com/victronenergy/gui-v2/issues/1268)

[martinbosma]

I will create recordings for venus-docker next week to test this. I'm not available for assistance from 5-26th of August.

[martinbosma]

I've added simulation gdf for Fischer Panda AGT and gdh for Hatz gensets to venus-docker.

[blammit]

PageGensetModel: use /Error/0/Id

Note: this will be addressed by https://github.com/victronenergy/gui-v2/issues/1268 so it can be ignored as part of this task. I'll update this task description to mention this.