Support skip lock and no wait

[si3nloong]

https://dev.mysql.com/blog-archive/mysql-8-0-1-using-skip-locked-and-nowait-to-handle-hot-rows/

[si3nloong]

Example of Queries:

SELECT seat_no, row_no, cost
FROM seats s JOIN seat_rows sr USING ( row_no )
WHERE seat_no IN ( 3,4 ) AND sr.row_no IN ( 5,6 )
AND booked = 'NO'
FOR UPDATE OF s SKIP LOCKED;

SELECT seat_no
FROM seats JOIN seat_rows USING ( row_no )
WHERE seat_no IN (3,4) AND seat_rows.row_no IN (12)
AND booked = 'NO'
FOR UPDATE OF seats SKIP LOCKED
FOR SHARE OF seat_rows;

Proposed API designs:

1. Using chain function

options.LockForUpdate().NoWait()
options.LockForUpdate().SkipLocked()

2. Separate with different expr

options.LockForUpdate()
options.LockForUpdate("columnA")
options.LockForUpdate(expr.Pair("db", "columnB"))

options.LockForUpdate(expr.NoWait())
options.LockForUpdate(expr.NoWait("columnC"))
options.LockForUpdate(expr.NoWait(expr.Pair("db", "columnB")))