Use CancellationTimeout to set timeouts for KILL QUERY command

[bgrainger]

There are two hard-coded three-second timeouts when cancelling a query:

MySqlConnector/src/MySqlConnector/MySqlConnection.cs

Line 709 in 33023cf

csb.ConnectionTimeout = 3u;

MySqlConnector/src/MySqlConnector/Core/ServerSession.cs

Line 128 in 33023cf

killCommand.CommandTimeout = 3;

It seems like these should be initialised from CancellationTimeout (in the connection string) instead. If the user needs to raise that for their database, they probably need these timeouts to be longer, too.

[bgrainger]

Fixed in 1.3.0.