[roji]

Fixes #3566.

Backports the complete merged change from #4067 (c1ac3e1) to hotfix/10.0.4, including the complex-mapping regression and final visitor comments.

Extract affected json_to_recordset/jsonb_to_recordset binary fields as text and rewrite their references to decode(column, 'base64'), preserving the binary type mapping. The production fix is unchanged from main and runs after relational postprocessing, keeping the generated SQL flat without wrapper subqueries.

EF10 has no JsonTranslationsNpgsqlTest, so adapt the regression to its existing AdHocJsonQueryNpgsqlTest suite. Cover complex JSON collections with both json and jsonb, sync/async execution, exact bytes [0, 1, 127, 128, 255], empty arrays, null values, full-document materialization, collection projection, server-side equality, and exact SQL assertions. No dependency changes.

Validation against a dedicated PostgreSQL 18 container:

• All four regression cases reproduced the incorrect base64-text bytes before the fix and pass afterward.
• Focused ad-hoc/shared JSON collection and projection suites: 656 passed, 8 skipped, 0 failed.

Related upstream reference: dotnet/efcore#33440, the sibling SQL Server scalar fix rather than shared EF code replacing this PostgreSQL patch.