RUSTSEC-2021-0022 Use-after-free in `subscript_next` and `subscript_prev` wrappers

Affected versions of this crate had an unsound implementation which could pass a pointer to freed memory to ydbsubscriptnextst and ydbsubscriptprevst if the variable and subscripts did not have enough memory allocated on the first call to hold the next variable in the database. For example, the...