[Feature request] Selecting ranges manually on a multimeter

[chille]

There is no way to manually select a range on a multimeter. Everything is hardcoded to auto range.

This might not be a big problem if you have a high end multimeter, which is quick as duck to select the appropriate range. But on a cheaper multimeter this could be painfully slow. It gets even worse on some instruments. I think the OWON XDM1000 benchtop multimeter can only auto range in one direction.

I will continue my journey into the scopehal source and see if I can figure out a way to implement this. @azonenberg said he could take a look at UI and HMC8012 parts.