Bump up the maximum number of profiles from 4 to 6

[bsstephan]

Step 5 (and probably 4) of the roadmap at #1123. I'm pretty sure the previous steps excised most if not all of the places in the firmware where we hardcoded 4; now that we have to support <4, I think we are using the dynamic count everywhere, but I'll have to check. Assuming I'm right, we just need to increase the maximum in the .proto file and React code and bump the amount of reservation for the config, since we're just about at our limit anyway.

Targeting v0.7.11 (or whatever the next release ends up being).