meson: Detect Linux distro and choose an appropriate init style

[rdmark]

Use /etc/os-release to detect which Linux distro we are running on.

[rdmark]

There are surely other Linux distros that are worth detecting, but I used the ones that I have handy to actually test.

[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 SonarCloud

[rdmark]

The distro detection here is fairly loose. I tried doing exact matches with e.g. ID=alpine but found that some distros put the id in quotation marks and some don't, while Meson does not support regular expression matching. So for now I do a global match for the distro keywords, which means that ID_LIKE fields will get matched too. For instance, Mint will be detected as Ubuntu since I don't have an explicit check for Mint:

ID=linuxmint
ID_LIKE=ubuntu