Add retryable errors for deadlock and lock wait timeout

[dharkness]

Adds two retryable lock-related errors:

• 1205: ER_LOCK_WAIT_TIMEOUT
  Lock wait timeout exceeded; try restarting transaction

• 1213: ER_LOCK_DEADLOCK
  Deadlock found when trying to get lock; try restarting transaction

[daniel-nichter]

Thank you for the commit. Very ironic timing with #3 that adds lock wait time. Since PR 3 has a test (and was submitted first), let's merge that one first. Then could reuse your work off that?

[dharkness]

Yeah, I saw #3 after submitting my PR. I saw no changes for a while so wasn't sure if you'd want the PR, but if so I can add a test and rebase after you merge the other PR. Thanks for creating this package.