Commander: Introduce global_position_relaxed (#24280)

To separate accuracy requirements for VTOL hover and cruise.

- global_position_relaxed refers to having a valid horizontal velocity aid source 
in the estimator and a set global reference position, but poses no requirements 
on the accuracy of the provided position estimate. 
- Auto flight modes Mission, Loiter and RTL, while in fixed-wing mode, 
only require the relaxed global position going forward
- COM_POS_FS_EPH is thus no longer used on fixed-wing vehicles (resp. VTOL in FW)
- rename failsafe_flags.local_position_accuracy_low to failsafe_flags.position_accuracy_low
---------

Signed-off-by: RomanBapst <bapstroman@gmail.com>
Signed-off-by: Silvan Fuhrer <silvan@auterion.com>
Co-authored-by: Silvan <silvan@auterion.com>

msg/versioned/Event.msg

@@ -0,0 +1,12 @@
+# Events interface
+uint32 MESSAGE_VERSION = 1
+
+uint64 timestamp			# time since system start (microseconds)
+
+uint32 id                   # Event ID
+uint16 event_sequence       # Event sequence number
+uint8[25] arguments         # (optional) arguments, depend on event id
+
+uint8 log_levels            # Log levels: 4 bits MSB: internal, 4 bits LSB: external
+
+uint8 ORB_QUEUE_LENGTH = 16