Catch internal vars

New Issue Checklist

• [x ] Updated SwiftLint to the latest version
• [x ] I searched for existing GitHub issues

Describe the bug

The ideia is to find internal vars on the code, but for some reason is not catching group 4, does SwiftLint support name grouping like ? and on yml capture_group: "internal"? the regex is working on Xcode 11 regex find

Complete output when running SwiftLint, including the stack trace and command used

original regex

(.*\n)*?class\s\w*\s?[:](\s+\w*[:, {])*\{\n(.*\n)*?((\s{4}|\t)(internal\s)?((weak|lazy)\s)?(var|let))

//
//  Copyright © whatever
//

import Foundation

open class SomeViewModel: NSObject {

    open var someService: SomeService

    public init(someService: SomeService) {
        self.someService = SomeService
    }

    //internal var stuff = 1 // <--if uncommented should catch this one 

    open var stuff12 = 1

    internal var stuff = 1 // <--should catch this one 
}

Environment

• SwiftLint running on Xcode with custom rules

internal_acl: 
      included: ".*((View|ViewController|ViewModel|Cell).swift)\\b$"
      name: "Delivery Internal access level"
      regex: "(.*\\n)*?class\\s\\w*\\s?[:](\\s+\\w*[:, {])*\\{\\n(.*\\n)*?((\\s{4}|\\t)(internal\\s)?((weak|lazy)\\s)?(var|let))"
      capture_group: 4
      message: "Please make sure to not use internal access level so that delivery could customize or access this variable.For more information check https://wiki.smithmicro.net/display/SP/iOS+Extensibility+Guidelines"
      severity: error

Reproduce the report with the supplied custom-rule YAML and Swift sample, then inspect SwiftLint's custom regex rule handling and capture_group parsing. No repository file or test is named in the issue; compare the configured group 4 with the existing behavior. Done means the internal declaration is consistently caught or the supported configuration is established by a regression test.