feat(mavlink): adopt the kaptan-native dialect

firmware/libs/kaptan-mavlink/definitions/publish/optical_flow.xml

@@ -0,0 +1,14 @@
+<?xml version="1.0"?>
+<mavlink>
+  <version>3</version>
+  <dialect>0</dialect>
+  <messages>
+    <message id="51030" name="OPTICAL_FLOW">
+      <description>One accepted ground-referenced optical-flow observation from the board's selected vertical sensor route.</description>
+      <field type="uint64_t" name="time_us">Flight-controller monotonic reception time in microseconds.</field>
+      <field type="int32_t[2]" name="velocity_millimetres_per_second">Ground-referenced sensor-frame X/Y velocity in millimetres per second.</field>
+      <field type="uint32_t" name="ground_distance_millimetres">Ground distance in millimetres.</field>
+      <field type="uint8_t" name="quality">Device-reported observation quality.</field>
+    </message>
+  </messages>
+</mavlink>