Adds send_with_timeout() to CarryoutG2Protocol for long-running
commands, and az_sweep_firmware() to both SerialBridge and DemoDevice.
Sweep and Sky Map modes now try the firmware path first (single
azscanwxp command, streaming results) and fall back to software
step-dwell-measure on error or when "Software mode" checkbox is
checked. Software sweep fixed to set EL once and move AZ only.
Ryan Malloy
3cd6424168