fw rate: add gain compression algorithm

msg/CMakeLists.txt

@@ -98,6 +98,7 @@ set(msg_files
 	GeneratorStatus.msg
 	GeofenceResult.msg
 	GeofenceStatus.msg
+	GainCompression.msg
 	GimbalControls.msg
 	GimbalDeviceAttitudeStatus.msg
 	GimbalDeviceInformation.msg

msg/GainCompression.msg

@@ -0,0 +1,6 @@
+uint64 timestamp                # Time since system start (microseconds)
+
+float32[3] compression_gains	# [-] Multiplicative gain to modify the output of the controller per axis [@frame FRD], [@range 0, 1]
+float32[3] spectral_damper_hpf  # Squared output of the spectral damper’s high-pass filter [@frame FRD]
+float32[3] spectral_damper_out  # Spectral damper's output squared [@frame FRD]
+float32[3] input                # Torque input [@frame FRD]