[Improvement] Fix column schema_id inconsistency when table namespace and columns change together

### What would you like to be improved?

When updating a table, TableColumnMetaService.updateColumnPOsFromTableDiff only calls updateSchemaIdByTableId(...) when there are no column diffs. If namespace changes and columns are also added/updated/deleted in the same update, that branch is skipped. This can leave active non-deleted column rows with stale old schema_id, creating inconsistent column metadata for the same table.

### How should we improve?

In updateColumnPOsFromTableDiff, handle namespace migration independently from column diff emptiness. If the namespace changed, always align existing active column rows to the new schema_id (either by always calling updateSchemaIdByTableId(...) before inserting diff rows, or by ensuring all surviving rows for that table/version get a new schema_id). Keep the current diff-insert logic for UPDATE/DELETE records, and add a unit test that updates the namespace and columns together and verifies that no active non-deleted column remains under the old schema_id.

Here's a unit test to help:
```
@TestTemplate
public void testUpdateTableWithSchemaAndColumnChangesUpdatesAllColumnSchemaIds()
throws IOException {
String catalogName = "catalog1";
String oldSchemaName = "schema1";
String newSchemaName = "schema2";
createParentEntities(METALAKE_NAME, catalogName, oldSchemaName, AUDIT_INFO);
createAndInsertSchema(METALAKE_NAME, catalogName, newSchemaName);

ColumnEntity existingColumn =
ColumnEntity.builder()
.withId(RandomIdGenerator.INSTANCE.nextId())
.withName("column1")
.withPosition(0)
.withComment("comment1")
.withDataType(Types.IntegerType.get())
.withNullable(true)
.withAutoIncrement(false)
.withDefaultValue(Literals.integerLiteral(1))
.withAuditInfo(AUDIT_INFO)
.build();

TableEntity createdTable =
TableEntity.builder()
.withId(RandomIdGenerator.INSTANCE.nextId())
.withName("table_move_schema")
.withNamespace(Namespace.of(METALAKE_NAME, catalogName, oldSchemaName))
.withColumns(Lists.newArrayList(existingColumn))
.withAuditInfo(AUDIT_INFO)
.build();
TableMetaService.getInstance().insertTable(createdTable, false);

ColumnEntity newColumn =
ColumnEntity.builder()
.withId(RandomIdGenerator.INSTANCE.nextId())
.withName("column2")
.withPosition(1)
.withComment("comment2")
.withDataType(Types.StringType.get())
.withNullable(true)
.withAutoIncrement(false)
.withDefaultValue(Literals.stringLiteral("v2"))
.withAuditInfo(AUDIT_INFO)
.build();

TableEntity movedAndUpdatedTable =
TableEntity.builder()
.withId(createdTable.id())
.withName(createdTable.name())
.withNamespace(Namespace.of(METALAKE_NAME, catalogName, newSchemaName))
.withColumns(Lists.newArrayList(existingColumn, newColumn))
.withAuditInfo(AUDIT_INFO)
.build();

TableMetaService.getInstance()
.updateTable(createdTable.nameIdentifier(), old -> movedAndUpdatedTable);

long newSchemaId =
EntityIdService.getEntityId(
NameIdentifier.of(METALAKE_NAME, catalogName, newSchemaName), Entity.EntityType.SCHEMA);
ColumnPO existingColumnPO =
TableColumnMetaService.getInstance().getColumnPOById(existingColumn.id());

Assertions.assertEquals(
newSchemaId,
existingColumnPO.getSchemaId(),
"Existing column schema id should be updated to new schema id");
}
```