RTK_Everywhere firmware is now able to use the LG290P firmware update support

[LeeLeahy2]

This pull request includes the following commits:

• Define and use LG290P_MAX_PAYLOAD_BYTES for firmware updates
• Add fwCheckResponseStatus to verify response status
• Remove duplicate code, use common cleanup code instead
• Remove duplicate code, use fwCheckResponseStatus instead
• Don't pass packetNum to fwSendPacket, use _fw.packetNumber instead
• Use fwCheckResponseStatus in fwSendPacket
  Also manage _fw.packetNumber
  Reset _fw.accumLen
• Remove dead code
• Rename bytesToWrite to bytesToAdd
• Remove dataIdx from updateFirmware
• Handle the last packet in updateFirmware
• Retry the erase operation when it fails
• Update the version to 3.1.2