dataURL should be false by default

[itpropro]

Describe the feature

I understand the motivation behind having a detection for base64, as undio in focused on io (as by the name xD) but I think the dataURL shouldn't be true by default.
I don't think it would be expected behavior if I want to convert a text or an array to base64 that I get a data url format back.
This would only be relevant in the context or content type handling in data context, but is quite confusing for normal base64 handling inside of an application.

What do you think @pi0 ? I think it should at least be highlighted in the docs, which I am of course willing to adjust.

Additional information

• Would you be willing to help implement this feature?