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
work-in-progress as it still needs improvements to the comments in order to
be useful as a template.
FossilOrigin-Name: 22358fb5495c727a4dde129128fe409a7b929a5ffa143b1e2879f84d7680ec3c