Correct Go interface definition error codes and Arrow type

WriteTableTablet checks the column count before matching names, so a
tablet that omits or adds a column returns ErrInvalidSchema rather than
ErrColumnNotExist; only a column name absent from the schema yields
ErrColumnNotExist. Say that instead of calling any missing column
ErrColumnNotExist.

arrow.TimestampType implements arrow.DataType with pointer receivers,
so the type mapping has to show &arrow.TimestampType{...}; the value
form does not compile against arrow-go v18.