User/Apps247/764-check-iridium-connection-strength

[Apps247]

Description

• Resolves Local Transceiver: update send() and debugsend() to check connection before using satellite and look into clearing buffer before reading #764
• Added function checkIridiumSignalQuality(), and ros service check_signal_quality
• Fixed serial read timeouts not working, which were causing pieces of the program to hang.
• Added time sleep delays in the debugSendAT() and send() function to avoid clear buffer and read form buffer operations clashing when using hardware modem.
• Added corresponding new constants for signal quality in at_cmds.h and for timeouts in local_transceiver.h
• Changed remote transceiver and sailbot db tests to fail instead of error out if couldn't establish connection (because password isn't correct)

Verification

• Run checkIridiumSignalQuality test (uses virtual Iridium)
• Call ros service check_signal_quality. Should timeout if no model connection, or should give a message with a signal from 1 to 5.

[lross03]

Most changes were approved in #714 , new changes are also good