Add issuerID as special signal in validators + fix vulnerability

[daveroga]

• Add issuerID as special signal in validators V2 and V3
• Add check of special signals after proof submit in test
• Fix high severity vulnerability for cross-spawn

[coveralls]

Pull Request Test Coverage Report for Build 12009455725

Details

• 7 of 7 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+1.5%) to 84.67%

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Totals
Change from base Build 11835520670:	1.5%
Covered Lines:	1016
Relevant Lines:	1127

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💛 - Coveralls

[vmidyllic]

please bump contracts version for validators and package.json