Is there something like "Windows Subsystem for Linux" for android oficially supported? I am mainly interested in apt-get or snap for commandline applications.
No, there is no such thing as Windows subsystem for Linux for Android. If your primary concern is using apt-get or snap on Android, then you may try Ubuntu touch based phones who use Ubuntu OS and snap.
I also found this app that says it can install Linux distro on Androids. Check here https://play.google.com/store/apps/details?id=com.zpwebsites.linuxonandroid&hl=en
Related question on Android SE - https://android.stackexchange.com/questions/59863/a-real-terminal-root-or-no-root