cmake: set RPATH of installed mavsdk_server

[julianoes]

This allows to install the mavsdk_server binary in any install prefix and run it.

[JonasVautherin]

Won't this always inject an rpath, even when the intent is actually to use system dependencies?

Also does it inject relative paths or absolute paths? It feels like CMAKE_INSTALL_PREFIX may be absolute, right?

[julianoes]

I don't think you ever want to use system dependencies with mavsdk_server, because you build mavsdk, mavsdk_server, and mavsdk_server_bin at the same time and install it together, locally or system wide.

Yes, CMAKE_INSTALL_PREFIX is absolute, but it does work, and without it, it doesn't work.

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[JonasVautherin]

and without it, it doesn't work.

Yeah without it you probably have to set LD_LIBRARY_PATH, which is inconvenient. I was just concerned that this may inject paths into some system packages people may distribute.

[julianoes]

Let's merge it and check the release once done.