LibSQL: Don't interpret AK::Error codes as SQL error codes
This makes error invocations such as Error::from_string_literal become
associated with a SQLErrorCode (typically 0, AmbiguousColumnName). The
result, when displayed to the user, is quite confusing, e.g.:
Column name 'Heap()::write_block(): Oversized block' is ambiguous
Instead, just interpret these as internal errors, so the error message
is displayed as-is.