Tests

Make max read size configurable #911

Job	Run time
unit	4m 27s
e2e (TestMultipleChainHorcrux)	32m 32s
e2e (TestChainPureHorcrux)	5m 7s
e2e (TestDownedSigners2of3)	7m 2s
e2e (TestDownedSigners3of5)	7m 11s
e2e (TestLeaderElection2of3)	5m 17s
e2e (Test2Of3SignerThreeSentries)	4m 58s
e2e (Test2Of3SignerThreeSentriesUniqueConnection)	4m 59s
e2e (TestUpgradeValidatorToHorcrux)	5m 6s
e2e (TestSingleSignerTwoSentries)	5m 1s
e2e (TestHorcruxProxyGRPC)	5m 9s
	1h 26m 49s

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