add operator support for updating columns of array types

[0x777]

To begin with, we can add support for _append and _prepend like we do for json types.

[0x777]

via Pum on discord

[mwaldstein]

Related to #348

My specific interest is in having support for '_contains' with integer[] Arrays

[manasag]

This issue will now be reviewed and tracked as part of the Hasura V3 roadmap.