Reset stmt when done

[ruslandoga]

Handles https://github.com/elixir-sqlite/exqlite/pull/298#discussion_r1792822558

[...] In the future, it should be called once we are done with the statement rather than before using it since otherwise SQLite would be wasting resources by keeping finished but non-reset statements.

It also improves bind/2 performance since it doesn't have to go through dirty scheduler for a reset/1 call anymore.