Ublox add UBX-RXM-RTCM for RTCM input status

[AlexKlimaj]

This PR adds support for the UBX-RXM-RTCM message which gives feedback on whether the ublox module is using the RTCM data that is being sent to it.

Requires PX4/PX4-GPSDrivers#130

I also discovered a bug in the uavcan rtcm publisher. When the mavlink stream goes down there is a chance that a second instance of the gps_inject_data topic is created. When that happens the uavcan publisher isn't setup to handle switching streams.

I mirrored the gps driver instance switching logic but discovered it will get stuck on a non existing gps_inject_data instance.

@julianoes Can you take a look?

nsh> gps status
INFO  [gps] Main GPS
INFO  [gps] protocol: UBX
INFO  [gps] status: OK, port: /dev/ttyS0, baudrate: 921600
INFO  [gps] sat info: disabled
INFO  [gps] rate reading:                  925 B/s
INFO  [gps] rate position:                1.00 Hz
INFO  [gps] rate velocity:                1.00 Hz
INFO  [gps] rate publication:             1.00 Hz
INFO  [gps] rate RTCM injection:         40.02 Hz
 sensor_gps
    timestamp: 244102098 (0.781204 seconds ago)
    timestamp_sample: 0
    time_utc_usec: 1684174039124558
    device_id: 11141125 (Type: 0xAA, SERIAL:0 (0x00))
    lat: 406203100
    lon: -1118287492
    alt: 1433548
    alt_ellipsoid: 1414764
    s_variance_m_s: 0.76600
    c_variance_rad: 2.39044
    eph: 6.32000
    epv: 10.58200
    hdop: 1.12000
    vdop: 1.75000
    noise_per_ms: 72
    jamming_indicator: 13
    vel_m_s: 0.18500
    vel_n_m_s: -0.00900
    vel_e_m_s: 0.18500
    vel_d_m_s: -0.06700
    cog_rad: 5.42557
    timestamp_time_relative: 0
    heading: nan
    heading_offset: -1.57080
    heading_accuracy: 0.00000
    rtcm_injection_rate: 40.01656
    automatic_gain_control: 0
    fix_type: 4
    jamming_state: 2
    spoofing_state: 1
    vel_ned_valid: True
    satellites_used: 11
    selected_rtcm_instance: 0
    rtcm_crc_failed: False
    rtcm_msg_used: 2

[dagar]

Nice!

[DronecodeBot]

This pull request has been mentioned on Discussion Forum for PX4, Pixhawk, QGroundControl, MAVSDK, MAVLink. There might be relevant details there:

https://discuss.px4.io/t/px4-maintainers-call-may-16-2023/32137/1

[julianoes]

Looks correct!

[AlexKlimaj]

I think we need to rework the instance switching logic to avoid the bug I ran into. @dagar suggested we always subscribe to both but only use one.

[AlexKlimaj]

GPS submodule PR is in. Submodule now points to the most recent commit in the GPS main branch.

[julianoes]

Let's get it in.

[julianoes]

I cleaned up the commits, rebased on top of main and force-pushed. I'll merge it if CI doesn't look worse than main.

[julianoes]

I assume CI is unrelated.