Add Fallback.ToDefaultLanguage

[ronaldbarendse]

Prerequisites

• I have added steps to test this contribution in the description below

If there's an existing issue for this PR then this fixes #8349.

Description

This add a new fallback value (4) to get the content/property value from the default language, instead of the configured language fallback chain.

This is currently a draft, as it needs some unit tests to verify the functionality and additional documentation about why this a much needed addition/feature.

[umbrabot]

Hi there @ronaldbarendse!

Thanks so much for your contribution! We wanted to let you know that we love the content! Unfortunately, we have spent some time looking at the open PRs for the last minor release of Umbraco 8 and we have decided that while the work is great, we have decided not to merge this.

We hope to make 8.18 an umbazing release so we took the time to assess each contribution during our CMS workshop. If you would like to know a little more about that process, take a look at this article.

We would, however, be super happy to merge this into Umbraco 9. If you would be happy to take a look at how you could adapt this for Umbraco 9, please raise a PR and we'll take a look! For info on how to get started with Umbraco 9, check out these docs.

In the meantime, a big #H5YR goes out to you for your fine work here.

Thanks, from your friendly Umbraco GitHub bot 🤖 🙂