PYTHON-5518: withTransaction API retries too frequently

[sleepyStick]

PYTHON-5518

Summary

_BACKOFF_INITIAL, _BACKOFF_MAX, and the growth rate have now been experimented with using the previous with_transaction benchmark and values are chosen based on what experimentally did the best.

Changes in this PR

• added tests for the backoff in with_transaction

• changed _BACKOFF_INITIAL, _BACKOFF_MAX, and the growth rate

• graph.py was the file used to analyze the various _BACKOFF_INITIAL, _BACKOFF_MAX, and the growth rate values against each other

• withTransaction.py was the benchmarking script
  happy to remove them or put them elsewhere but since this is just merging into the backpressure branch, i figured it was fine to keep for now?

Testing Plan

prose test

Screenshots (optional)

Checklist

Checklist for Author

• Did you update the changelog (if necessary)?
• Is the intention of the code captured in relevant tests?
• If there are new TODOs, has a related JIRA ticket been created?

Checklist for Reviewer {@primary_reviewer}

• Does the title of the PR reference a JIRA Ticket?
• Do you fully understand the implementation? (Would you be comfortable explaining how this code works to someone else?)
• Have you checked for spelling & grammar errors?
• Is all relevant documentation (README or docstring) updated?

Focus Areas for Reviewer (optional)