Context validation rules builder class

[koloml]

Is your feature request related to a problem? Please describe.
Currently, some of the commands contain special object with validation rules in the static property. This property is used by CommandContextValidator to check if context fits the rules. Main issue of this property is that it's documented in JSDoc and without this comment presented, this property will not give any hints about available and valid properties.

Describe the solution you'd like
I think it'll be better if these rules will be generated using some sort of builder class with the methods for all available options. Usage of this class might look like this:

class ExampleCommand extends BaseCommand {
  // Logic of the command
  
  static validators = new ValidatorBuilder()
    .requireCallerPermission("ADMINISTRATOR")
    .maxArguments(2)
    .minArguments(1)
    .argumentVariants(['option1', 'option2'])
    .argumentRegexp(/^option[12]$/)
}

With class like this it'll be easier to implement new features for the context validation and keep track of already existing ones.

Describe alternatives you've considered
—

Additional context
Example of the command with validators:
https://github.com/thecorecity/cognitum/blob/master/lib/commands/guild/LogSettingsCommand.js