xShadowName method is added to the sqlite3_module object and is used
to identify potential shadow tables. The SQLITE_PREPARE_SHADOW argument
to sqlite3_prepare_v3() is defined. It is designed to permit writing to
shadow tables, but is currently an unused placeholder.
FossilOrigin-Name: 31942b3dd3f66eb0d9977bf1cadc2f2d7be7967cce2b55784be0b939dfef1985
(1) Add an extra "schema" column to show the schema name for ZIPVFS stats.
(2) Only show ZIPVFS stats to schema that use ZIPVFS
(3) Put a NULL in unused columns of the output.
FossilOrigin-Name: 9351135b4331107be2f2bda7b6adbd5436381f4f9a68340e8a172b6517ec3f12