[1.x][2.0.x] Option to retrigger popup instead of trying to prevent it when no policy version is set

Problem/Motivation

If version cookie doesn't exist, some use cases do want to retrigger the popup.

Steps to reproduce

1. Agree to to cookie policy before the module has the Cookie Policy Version feature #2987584: Terms version change (GDPR regulation)
2. Update to a module version which has that feature
3. Surf to the website again and notice you won't have to re-agree, while some use cases would like this

Proposed resolution

We removed:

      if (typeof Drupal.eu_cookie_compliance.getVersion() === 'undefined') {
        // If version doesn't exist as a cookie, set it to the current one.
        // For modules that update to this, it prevents needless retriggering
        // For first time runs, it makes no difference as the other IF statements
        // below will still cause the popup to trigger
        // For incrementing the version, it also makes no difference as either it's
        // a returning user and will have a version set, or it's a new user and
        // the other checks will trigger it.
        Drupal.eu_cookie_compliance.setVersion();
      }

But it'd probably better to keep that as default behaviour and introduce a setting to skip this behaviour.

Remaining tasks

Patch, test, ...

User interface changes

Yes. Configuration option addition.

API changes

None.

Data model changes

None.