Fix bug using multiple zip files
  modified:   storage/connect/filamzip.cpp
  modified:   storage/connect/filamzip.h
  modified:   storage/connect/tabfmt.cpp
  modified:   storage/connect/tabjson.cpp

- Add error msg when trying to make discovery on multiple tables
  modified:   storage/connect/tabfmt.cpp
  modified:   storage/connect/tabjson.cpp
  modified:   storage/connect/tabxml.cpp