Tools: complete rewrite of the ESC-configuration state machine

Co-authored-by: Dr.-Ing. Amilcar do Carmo Lucas <amilcar.lucas@iav.de>

tidy message sending using templates
Calculate and enforce the minimum update period.
Disable unused features to save flash
forced time gaps between all transmits
correct ESC reset functionality
Avoid re-initialization repeatition
Make sure we stop FETtec if safety is on (ignore reverse) this reduces duplicated code
Error count calculation changed
   as the telemetry error count is absolute only the overflow status can be safed and used for the percentage calculation
Update the README to add autotests information
FETtec needs a time gap between frames
  This allows running at high fast_loop_rates
do not send fast_throttle data if a configuration command just got sent
Example parameter configuration file is for a Quadcopter with ESCs connected to Telem2
remove two FIXME
fix compilation in master
Fix the ESC not re-initializing issue.
  Now we re-init whenever we loose connection
RVMASK parameter changes only take effect when not armed
Improve documentation
Always use the same wording when referring to fast-throttle commands
fix pre-arm check message
assure the length of the memmove is positive
Set HAL_AP_FETTEC_CONFIGURE_ESCS to 0 when no ESC hardware is available and you want to test the UART send function

Tools/autotest/arducopter.py

@@ -7247,7 +7247,7 @@ class AutoTestCopter(AutoTest):
             if self.get_sim_time_cached() - tstart > 20:
                 raise NotAchievedException("Expected mask to be only problem within 20 seconds")
             try:
-                self.assert_prearm_failure("Invalid motor mask; need consecuti")
+                self.assert_prearm_failure("Invalid motor mask")
                 break
             except NotAchievedException:
                 self.delay_sim_time(1)