Allow setting custom pins for ina219.cpp, add ina to main central mast

See merge request !29

# Conflicts:
#	client/libs/espnow/src/ESPNow.cpp
#	client/libs/espnow/src/Message.cpp
#	host/host_central_mast/src/main.cpp

Moved RS485 Return Types to ErrorTypes
Changed a MeasurementType for INA219
Moved ErrorType from ClientDataPackage to Measurement
WIP: Started specifying errors from sensor readouts

moved mac storage to singleton, tried to reduce response time

See merge request !26

Minor additions to host

See merge request !25

# Conflicts:
#   host/host_central_mast/src/main.cpp

Refactor of Host ESP32

See merge request !24

Move SD card specific utilities into their own namespace
Try remounting SD after a number of failed attempts (see Definitions.h)
Early exit continuous SD access if the SD has not been found before.