Implement the get failover log test cases

1. Try to get failover log with no upr connection created

• Send a get failover log request. Expect the connection to be disconnected

2. Try to get the failover log for a consumer connection

• Open a consumer connection
• Send a get failover log request. Expect the connection to be disconnected

3. Get the failover log from a producer

• Open a producer connection
• Get the failover log and expect success
• Get "stats failovers"
• Check that the failover log you got from the upr connection matches the one if "stats failovers"

4. Get the failover log for a non-existent vbucket

• Open a producer connection
• Send a get failover log for a non-existent vbucket and expect a not my vbucket error