perf(GraphQL): Part-4: Child auth queries are derived from auth filtered parents (GRAPHQL-854)

[abhimanyusinghgaur]

This PR optimizes auth query rewriting by deriving child auth queries from auth filtered parents instead of all possible parents. This reduces the number of touched_uids at deep levels. This performance benefit comes into effect when there are a lot of nested levels in auth rules.

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This change is 

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[pawanrawal]

also check if ordering at root with filter and auth works correctly in a separate PR and add an e2e test for that

Reviewed 4 of 4 files at r1.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @abhimanyusinghgaur and @MichaelJCompton)

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graphql/resolve/query_rewriter.go, line 969 at r1 (raw file):

	// This query aggregates all filters and auth rules and is used by root query to filter
	// the final nodes for the current level.
	// User6 as var(func: uid(User2), orderasc: ...) @filter((eq(User.username, "User1") AND (...Auth Filter))))

check if orderasc is applied here

[abhimanyusinghgaur]

Reviewable status: 3 of 4 files reviewed, 1 unresolved discussion (waiting on @MichaelJCompton and @pawanrawal)

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graphql/resolve/query_rewriter.go, line 969 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

check if orderasc is applied here

Done.