Initial commit with Line Error Resend control to tackle resend loops
with host >> printer high latency allowing GCode in flight.
eg, Octoprint>[wifi]>ESP3D>>Printer

Existing Resend method, clears RX_Buffer, sends request
    Unable to clear consecutive N lines already release from Octoprint
    host(In-flight). Printer receives expecting requested line,
    triggering additional resend request. Printer eventually receives
    correct line, multiple times, triggering further resend requests
    for next line.