Closes#1628. Every function that calls `process_overflow_read` needs
to be reentrant. I did not change it here, but it would include
`get_prev_record` and `get_next_record`. Maybe `tablebtree_move_to` did
not need to use the state machine, but I included it as a safeguard.
Edit: Closes#1625 . When I implemented `restore_context`, I forgot to
add a `return_if_io` after calling it in `next` 🤦♂️
Edit: Closes#1617 . Just tested it and it also solves this bug.
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#1636