Add LockBatch and fix scales

[olaeseane]

Add new function for group blocking utxos.

[coveralls]

Pull Request Test Coverage Report for Build 4667042900

• 65 of 102 (63.73%) changed or added relevant lines in 2 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.3%) to 57.319%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
extensions/token/balance_account.go	0	3	0.0%
extensions/token/balance_utxo.go	65	99	65.66%

Files with Coverage Reduction	New Missed Lines	%
gateway/chaincode_instance_event_service.go	1	75.27%

Totals
Change from base Build 4161119822:	0.3%
Covered Lines:	4002
Relevant Lines:	6982

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💛 - Coveralls