[hitl] rewrite support for hardware in the loop simulation (#3146)

- old way (based on ins_vectornav) is not supported anymore
- directly send sensor data and receive commands with a dedicated link
- examples with USB link for better results
- update sphinx documentation
- compilation in a single build

conf/modules/stabilization_attitude_fw.xml

@@ -54,7 +54,7 @@
     <file name="stabilization_attitude.h"/>
   </header>
   <init fun="h_ctl_init()"/>
-  <makefile target="ap|sim|nps|hitl" firmware="fixedwing">
+  <makefile target="ap|sim|nps" firmware="fixedwing">
     <file name="stabilization_attitude.c" dir="$(SRC_FIRMWARE)/stabilization"/>
   </makefile>
 </module>