WL#14522: InnoDB: Configuration to control clone donor timeout after network failure

During clone, if there is a short network outage between donor and recipient 
server, donor waits for network to restore, recipient to reconnect and resume 
cloning. The donor wait time currently is fixed at 5 minutes. As in bug scenario 
it could be helpful sometimes to wait for little longer.

It might allow user to shoot at his foot by configuring it too large - the 
accumulated redo could grow if the connection doesn't restore back.

We should not encourage user to pause and restore the network for long because of 
the accumulated delta (redo/page) in donor server. It is also going to affect 
clone restore time.

Related bug:
------------
BUG#102103 CLONING: WAIT FOR 15M INSTEAD OF 5M BEFORE DROPPING SNAPSHOT

F1: Have configuration to control the donor wait time for recipient to reconnect and restart cloning after a short network outage.

clone_donor_timeout_after_network_failure
Command-Line Format 	--clone-donor-timeout-after-network-failure

System Variable clone_donor_timeout_after_network_failure
Scope 	Global
Dynamic 	Yes
Type 	        Integer
Default Value 	5
Minimum Value 	0
Maximum Value 	30

Defines the amount of time in minutes the donor allows for the recipient to reconnect and restart a cloning operation after a network failure.