fbt: Deterministic STARTUP order & additional checks (#4179)

* unit_tests: clear startup order

* fam: ensure unique STARTUP order

* fbt: warn on same .order values within a group leading to non-determinitic builds

* fbt: better formatting for app order warning

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Co-authored-by: hedger <hedger@nanode.su>

applications/main/archive/application.fam

@@ -7,5 +7,5 @@ App(
     requires=["gui"],
     stack_size=4 * 1024,
     icon="A_FileManager_14",
-    order=0,
+    order=10,
 )