Rewrite APPLY over json_each into a join on SQLite

[Aykuttonpc]

SQLite doesn't support APPLY, so projecting a JSON collection currently fails with ApplyNotSupported. SQLite's table-valued functions can reference preceding tables in the FROM clause though, so the APPLY that EF produces for these queries can be expressed as a regular join.

This adds SqliteApplyFlatteningExpressionVisitor, which runs before the existing APPLY validator and rewrites CROSS/OUTER APPLY over a subquery whose only table is json_each into a CROSS/LEFT JOIN over that function, inlining the subquery's projection into the containing SELECT.

Json_collection_in_projection_with_anonymous_projection_of_scalars now translates to:

SELECT "j"."Id", "o"."value" ->> 'Name' AS "Name", "o"."value" ->> 'Number' AS "Number", "o"."key"
FROM "JsonEntitiesBasic" AS "j"
LEFT JOIN json_each("j"."OwnedCollectionRoot", '$') AS "o" ON 1
ORDER BY "j"."Id", "o"."key"

Scope

Only subqueries that do nothing beyond projecting out of json_each are rewritten:

Tables: [JsonEachExpression], Predicate: null, GroupBy: [], Having: null,
Orderings: [], Limit: null, Offset: null, IsDistinct: false

Lifting a predicate or a limit out of the subquery would change what the query means, so anything else still goes through the validator and reports ApplyNotSupported as before. That's why this says "Part of" rather than "Fixes".

Tests

The full SQLite functional suite passes (38367 tests, 0 failures). Nine tests that previously asserted ApplyNotSupported now run against the real query, so their overrides were removed:

• JsonQuerySqliteTest.Json_collection_in_projection_with_anonymous_projection_of_scalars
• ComplexJsonProjectionSqliteTest and OwnedJsonProjectionSqliteTest: SelectMany_associate_collection, SelectMany_nested_collection_on_required_associate, SelectMany_nested_collection_on_optional_associate

The SelectMany ones weren't something I targeted, they started working as a side effect of the rewrite.

One open question

The LEFT JOIN uses a constant true predicate, which renders as ON 1, since there is no real join condition. Let me know if you'd rather see something else there.

Part of #34375