Make the Validator constructor public, so we don't need to override it in the child class

[razvanbretoiu]

Make the Validator constructor public instead of protected.

Current implementation

The validator constructor is protected, and we always need to override it in the child validator

class MyValidator extends Validator<string> {
  constructor() {
    super();
  }
}
.
class MySchema extends Schema {
  @StringField({ validators: [new TimeZoneValidator()]})
  myField: string
}

We are forced by typescript to override the constructor, because we cannot use new TimeZoneValidator(), if the constructor is protected

Proposed solution

Make the constructor public, so we don't need to override it.