allow disabling all version update notifications on console

[rikinsk]

From #4096.

Allow users to opt out of all update notifications from the update notification bar (like for pre-release update noifications).

[celvin]

Or at least move it to a position where it won't be as annoying

[corysimmons]

This could be as simple as an env var like HASURA_DISABLE_UPGRADE_BANNER

Someone clicked the shiny button to upgrade from 1.x to 2.x several months ago and brought an entire prod site down for a week or two. 😣