Wrap a table-valued function in a derived table after LATERAL. Fix #1277

[azabluda]

Fixes #1277.

The defect

VisitCrossApply and VisitOuterApply already know that Firebird will not take a bare source after LATERAL: both special-case a TableExpression and emit (SELECT * FROM "T") AS "t". The same branch was missing for a TableValuedFunctionExpression, so a correlated queryable function came out as a bare call and the statement did not parse.

JOIN LATERAL "GetCustomerOrderCountByYear"("c"."Id") AS "g" ON TRUE
-- Dynamic SQL Error, SQL error code = -104, Token unknown

It now emits the wrapped form, with the alias on the derived table so the rest of the statement keeps referring to it unchanged:

JOIN LATERAL (SELECT * FROM "GetCustomerOrderCountByYear"("c"."Id")) AS "g" ON TRUE

Argument rendering goes through the existing GenerateList helper rather than a new loop.

Two commits, and the first is red on purpose

1. Un-skip the 14 correlated queryable-function tests, and create what they need.
Passed 82 -> 84, Failed 0 -> 12, Skipped 24 -> 10.

2. The fix. Failed 12 -> 0, Passed 84 -> 96.

Split this way so the fix is measured against a failing suite rather than asserted, and so each half can be reviewed on its own.

Two things you may not expect in here

The fixture was missing three objects. AddValues, GetCustomerOrderCountByYear and GetCustomerOrderCountByYearOnlyFrom2000 were never created, and nothing noticed, because every test that uses them was skipped. With the SQL fixed, those ten tests stop failing on Token unknown and start failing on Procedure unknown. They are ported from the definitions in EF Core's own UdfDbFunctionSqlServerTests fixture, in Firebird form: the two table-valued ones become selectable procedures, as the two already in this fixture are, and year(...) becomes extract(year from ...).

Two of the fourteen skips were already stale. QF_Select_Correlated_Subquery_In_Anonymous and QF_Correlated_Func_Call_With_Navigation pass with no product change at all.

Firebird versions

A correlated queryable function reaches the store as a LATERAL derived table, and LATERAL is Firebird 4 and later, so both the 14 tests and the three fixture objects are gated on ServerLessThan4() — the same early return NavigationsCollectionFbTest and ComplexTypeQueryFbTest already use.

The fixture guard is required rather than tidy. GetCustomerOrderCountByYearOnlyFrom2000 is 39 characters and Firebird 3 caps identifiers at 31, so creating it there fails the seed with Name longer than database column size and takes every test in the class down with it, including ones that pass today.

What was run

UdfDbFunctionFbTests, run locally:

Firebird
3.0	Passed 96, Failed 0, Skipped 10
5.0.3	Passed 96, Failed 0, Skipped 10

Full suites on 5.0.3: FirebirdSql.EntityFrameworkCore.Firebird.FunctionalTests Passed 14167, Failed 0, Skipped 1113, Total 15280; FirebirdSql.EntityFrameworkCore.Firebird.Tests Passed 102, Failed 0.

FB30, FB40 and FB50 are all green against Tests-EFCore and Tests-EFCore-Functional, run in my fork: https://github.com/azabluda/NETProvider/actions/runs/34167549531

Both wrapped and implicit forms were also run directly against the store by hand before the issue was filed.

AI usage

Per CONTRIBUTING: this change was written with Claude Code. I reviewed it, ran it and stand behind it. Both commits carry a Co-Authored-By trailer.