Enforce typing primitive parameters for certain functions

[krzysztofrewak]

I believe that would be really hard to do this for every function, but some of them are really common cases that we can cover by hardcoding it.

For example this:

json_decode($content, true);
in_array($key, $array, true);

should be written as this:

json_decode($content, associative: true);
in_array($key, $array, strict: true);

We should also think about other examples here.