[FIX] Preserve all translated fields on v16 migration

Currently, the upgrade process preserves translations only for Odoo CE+EE fields. However, databases usually have more modules (or even custom fields) and those translations get lost when upgrading to Odoo 16.

With this script, all translated fields will inherit their translations in all languages. Since it is executed in the `pre` phase of `base`, it should be able to still find the `ir_translation` table.

@moduon MT-7120

Author: yajo

src/base/16.0.1/pre-translations2jsonb.py

@@ -0,0 +1,63 @@
+"""Store ir.translation records in jsonb fields."""
+
+import logging
+
+from psycopg2.extras import Json
+from psycopg2.sql import SQL, Identifier
+
+from odoo.upgrade import util
+
+_logger = logging.getLogger(__name__)
+
+
+def migrate(cr, version):
+    already_converted = set()
+    missing_tables = set()
+    missing_columns = set()
+    cr.execute(
+        """
+        SELECT name, res_id, src, jsonb_agg(lang) AS langs, jsonb_agg(value) AS values
+        FROM ir_translation
+        WHERE res_id != 0 AND type = 'model' AND state in ('translated', 'to_translate')
+        GROUP BY name, res_id, src
+        ORDER BY src IS NOT NULL
+        """
+    )
+    for name, res_id, src, langs, values in cr.fetchall():
+        # Build a dict with all translations
+        all_values = dict(zip(langs, values, strict=True), en_US=src)
+        if not all_values["en_US"]:
+            all_values["en_US"] = all_values[langs[0]]
+        # Find the translation target table and column
+        model, field = name.split(",")
+        table = util.table_of_model(cr, model)
+        # Skip early if the translation is no longer usable
+        if not util.table_exists(cr, table):
+            missing_tables.add(table)
+            continue
+        if not util.column_exists(cr, table, field):
+            missing_columns.add(f"{table}.{field}")
+            continue
+        # Make sure the field is translatable in JSONB format (noop if done already)
+        if (model, field) not in already_converted:
+            util.convert_field_to_translatable(cr, model, field)
+            already_converted.add((model, field))
+        # Store updated translation
+        cr.execute(
+            SQL("UPDATE {table} SET {field} = %s WHERE id = %s").format(
+                table=Identifier(table),
+                field=Identifier(field),
+            ),
+            (Json(all_values), res_id),
+        )
+    # Log missing tables and columns
+    if missing_tables:
+        _logger.warning(
+            "Couldn't recover translation for these missing tables: %s",
+            ", ".join(sorted(missing_tables)),
+        )
+    if missing_columns:
+        _logger.warning(
+            "Couldn't recover translation for these missing columns: %s",
+            ", ".join(sorted(missing_columns)),
+        )