Skipping non used abstract Node type by default

[neos-bot]

Jira issue originally created by user @dfeyer:

Currently we export all Node types by default. VIE schema can become big when the website use a lots of abstract Node type, per exemple with an agency package that can contains a lots of default Mixins.

Jira-URL: https://jira.neos.io/browse/NEOS-530

[neos-bot]

Comment created by @johannessteu:

What kind of feedback do we need here [~dfeyer] ?

[neos-bot]

Comment created by @dfeyer:

I need to check on my local hard drive, ... i know I have something somewhere to show ;)

But I'm even not sure if it's a good idea, that's why the Need Feedback was set

Let's try to push some code, and ask for feed back on the PR ;)

[rolandschuetz]

@dfeyer Any updates?

[mhsdesign]

@Sebobo i think #3563 will fix this right?

[Sebobo]

@mhsdesign yes I think so