Add lock timeout in DistSQL

[terrymanu]

Add lock timeout in DistSQL LOCK CLUSTER WITH lockStrategy and UNLOCK CLUSTER.

The new attribute LOCK TIMEOUT should be optional. The SQL should be:

LOCK CLUSTER WITH lockStrategy (TIMEOUT int)? and UNLOCK CLUSTER (TIMEOUT int)?.

The todolist should be:

1. Update G4 file
2. Update LockClusterExecutor and UnlockClusterExecutor with Add todo on cluster lock #34133's TODO
3. Update document
4. Add test cases

[lubochen]

Hi @terrymanu ，could you please assign this issue to me? Thank you.

[terrymanu]

Great, welcome! @lubochen