Missed key access should return null instead of error

[alx3apps]

This example should return NULL instead of throwing error:

select json_get_text('{"foo":"qq", "bar": true}', 'foo1');
ERROR:  cannot extract from "{"foo":"qq", "bar": true}" json object by the key "foo1"

****** Error **********

ERROR: cannot extract from "{"foo":"qq", "bar": true}" json object by the key "foo1"
SQL state: 428094

It's necessary for LIKE requests over JSON column with different structure.
It's debatable whether returning NULL anywhere is sane practice (I think not), but here it's not possible for SQL requests to handle this error.
Also, functions already declared as return null on null input (for performance reasons).
Also, legacy java implementation returns nulls on missed keys

reported by grey