Delete deprecated code

[jasonlharvey]

It's time to delete some code that has been deprecated for a long time. Includes classes:

• GunnsFluidImpeller

• Converter

• ConverterElect

• EpsTripMgr

• ConverterSensors

• DiodeElect

• FetSwitchElect

• SolarArray

• SwitchCardElect

• GunnsSolarArrayRegulator

• [x] delete the classes

• [x] delete the associated unit tests and update test mains

• [x] remove resulting empty folders

• [x] update Doxygen groups

• [x] update make files

• [x] update CI scripts and references in various test & build scripts

• [x] remove them from any currently-maintained network drawings

• [x] remove them from GunnsDraw shape libraries

• [x] remove them from any currently-maintained sims

• [x] remove their wiki link help pages and any other references in the Wiki