Add support for non-default (1) vehicle ID (SYSID_THISMAV)

[goasChris]

Motivation:
Adds the possibility to use cockpit in multivehicle environments, where people may be using multiple tools to monitor/track different robots and be connected to several mavlink sessions.

I personally use 20+ robots, where I need to gather and track information from multiple at the same time, and our setup and system is built around identifying robots by their ID. It will also allow us to use cockpit to start testing more smoothly without having to tear down entire existing system.

Changes:

• Add detection, storage, and handling of system_id
  • Ardupilot has protected/export where we store the ID for later use
  • Updated all functions I could find where I believe it to be required
• Remove/adapt code that excludes all vehicles except for 1
• Update the VehicleFactory class to account for system_id, and use it when creating vehicles
• Updated all vehicles to be created with the system_id detected

Devices tested:

• Tested on SITL with our custom firmware, using mavlink router
• Tested on physical pi4 running custom rover variant firmware

Tests:

• Arm/Disarm with a vehicle id of 200
• Mode changes back and forth
• Messages, data/info/mavlink packets get displayed

[CLAassistant]

All committers have signed the CLA.

[rafaellehmkuhl]

Cool! I will take a better look at it on Monday!

And I think @patrickelectric and @Williangalvani will be helpful about your question regarding the target_system: 0.

[goasChris]

I got some input from an Ardupilot Dev. 0 is "Broadcast ID"

If the ids are omitted or set to zero then the message is considered a broadcast (intended for all systems/components).
Ref: https://mavlink.io/en/guide/routing.html

Based on this, I believe the correct action is to change the 0 (broadcast) to a specific system, as it is probably what is intended, and it's safer.

[rafaellehmkuhl]

I got some input from an Ardupilot Dev. 0 is "Broadcast ID"

If the ids are omitted or set to zero then the message is considered a broadcast (intended for all systems/components). Ref: https://mavlink.io/en/guide/routing.html

Based on this, I believe the correct action is to change the 0 (broadcast) to a specific system, as it is probably what is intended, and it's safer.

Totally. This was actually a bug by itself.

[goasChris]

Thank you very much for your patience @rafaellehmkuhl
What you said in the your code review made a lot of sense, and I have incorporated the requested changes.
Please give it another look when you have time, and I hope I didn't miss or misunderstand any of the requested changes :)

I've re-tested the basics (arm/dism, mode changes, messages, etc), and it seems to still work after making the changes.

[rafaellehmkuhl]

Nice!!

I think with those last changes we are good to go!

Excited to have this merged :)

[rafaellehmkuhl]

That seems perfect, Chris!!

Did you test this last version? If so, we are ready to merge!

[goasChris]

Sorry, wrong account.

Tests:
Yeah, again, just the basics. It builds, passes CI, mode changes and arm/dism, messages etc. Checked both vid 1 and 200.

[rafaellehmkuhl]

Perfect Chris! Thanks a lot for the contribution!