Fix imports of validation rules from 'graphql-js'

[IvanGoncharov]

For context please see: graphql/graphql-js#2402
@abernix it's a pre-request for 15.0.0 support.

[IvanGoncharov]

@abernix Can you update this peer dependency to 14.6.0?
It shouldn't be any breaking changes between 14.0.2 and 14.6.0 so it should be a pretty safe update for end-users.
But if it is not possible we can try to figure out other ways to support both ^14.0.2 and 15.0.0 in your code base.

[abernix]

@IvanGoncharov After graphql/graphql-js#2413 had been opened as a result of your conversation with @trevor-scheer, I was under the impression that we might not actually ship this PR right now. I now see #3741 has been opened as well (also, @trevor-scheer just went on vacation, so I'm unable to ask him).

I was believing that instead wait until we bump Apollo's major versions, which would be more appropriate for a major version update since peerDependencies don't otherwise give clear enough warning to users, but mostly because of the need for there to be exactly one copy of graphql in a project and the resulting problems that come from that with, e.g. the apollo CLI which brings graphql for its own purposes, even though apollo is expected work within a user's project which might need their own version requirement.

Again, we're happy to make these all happen in major version bumps, so maybe this PR and #3741 should just be targeted for our 3.x branch? (And we should start a similar branch, soon, on apollo-tooling — the home of apollo).

[abernix]

@IvanGoncharov @trevor-scheer Excuse me / Nevermind, I mis-analyzed this. While I think some parts of the above are true, I don't think #3741 needs to target a major version, though this one probably should.

[IvanGoncharov]

@abernix Yes definitely. I opened it before our Slack discussion and just forgot to close.