[Fix #10857] Add AllowedPatterns to Style/NumericLiterals.

[dvandersluis]

Allows additional allowed patterns to be specified for Style/NumericLiterals so that special patterns will not register offenses. The patterns are forced to be anchored (so \d{4}_\d{4} will only match exactly that, and not substrings), and this does not affect autocorrection, which will continue to add underscores between groups of 3 digits.

Fixes #10857.

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[koic]

Thanks!