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/px4_msgs_old/msg/ArmingCheckReplyV0.msg

@@ -0,0 +1,34 @@
+uint32 MESSAGE_VERSION = 0
+
+uint64 timestamp # time since system start (microseconds)
+
+uint8 request_id
+uint8 registration_id
+
+uint8 HEALTH_COMPONENT_INDEX_NONE = 0
+
+uint8 health_component_index      # HEALTH_COMPONENT_INDEX_*
+bool health_component_is_present
+bool health_component_warning
+bool health_component_error
+
+bool can_arm_and_run              # whether arming is possible, and if it's a navigation mode, if it can run
+
+uint8 num_events
+
+EventV0[5] events
+
+# Mode requirements
+bool mode_req_angular_velocity
+bool mode_req_attitude
+bool mode_req_local_alt
+bool mode_req_local_position
+bool mode_req_local_position_relaxed
+bool mode_req_global_position
+bool mode_req_mission
+bool mode_req_home_position
+bool mode_req_prevent_arming
+bool mode_req_manual_control
+
+
+uint8 ORB_QUEUE_LENGTH = 4

msg/px4_msgs_old/msg/EventV0.msg

@@ -0,0 +1,14 @@
+# this message is required here in the msg_old folder because other msg are depending on it
+# Events interface
+
+uint32 MESSAGE_VERSION = 0
+
+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