[CX] Upsert query gives wrong error message

This might be true for all dml operations.

Query issued:

UPSERT into default_shadow (key , value) VALUES ("key_arrayfcd3c", ['first1', 'second1']);

Error message:

	"msg": "Syntax error: In line 1 >>UPSERT into default_shadow (key , value) VALUES (\"key_arrayfcd3c\", ['first1', 'second1']);<< Encountered 'into' \"into\" at column 8. "

It should say upsert not supported.