[ocaml] apply a second topological sort to modules (#2793)

* [ocaml] apply a second topological sort to modules

After the first one, all functionalities are checked, but corresponding
modules are not ordered with the other one.
This second sorting algorithm (simpler) is just checking that final
selection of modules is correctly ordered and check for possible cyclic
dependencies not yet found.
ahrs_common dep node is fixed to avoid such a situation.

* [modules] trying to fix cyclic dependency in rotorcraft gnc modules

the main issue is that the rotorcraft navigation is not explicitely
included by the user but automagically included, which is not a good
idea, same goes for guidance.

* [modules] fix dep

system_core is already provided by firmware module and @no_settings
was making a cyclic dep for fbw

conf/modules/ahrs_common.xml

@@ -8,9 +8,6 @@
     </description>
     <configure name="AHRS_ALIGNER_LED" value="1" description="LED number to indicate AHRS alignment, none to disable (default is board dependent)"/>
   </doc>
-  <dep>
-    <depends>@ahrs</depends>
-  </dep>
   <header>
     <file name="ahrs.h" dir="subsystems"/>
   </header>