renew Session for session expired & reconnect connection of session for IOError

[Nicole00]

add re-execute operation, before re-execute, we should renew the session if the failure is E_SESSION_INVALID or E_SESSION_TIMEOUT, and we should reconnect the session's connection for IO Error, and just re-execute for E_EXECUTION_ERROR.

Don't retry for E_STATEMENT_EMPTY and E_SYNTAX_ERROR.

[wey-gu]

Sure, I can do this :) @Nicole00

[wey-gu]

#275

[wey-gu]

like implementations from, with (exponential)backoff-wise retry based on different exceptions.

https://github.com/jerryjliu/llama_index/blob/c528cf6857193a6056cfb2d77666ba3c5659750b/llama_index/graph_stores/nebulagraph.py#L170