Added Dutch translations

[bkiers]

A first version of Dutch Iconclass translations.

Various OpenAI/Deepl scripts used in this PR can be found here: https://github.com/Q42/iconclass-data/tree/txt_nl_2_3.txt/translation

The prompt used for translating English words/text to Dutch was the following:

Translate all text to Dutch taking the following rules into account:
- do not translate text surrounded by single quotes: such text needs to be included as-is;
- do not wrap text with quotes if the original text didn't have such quotes;
- if a word starts with a lower case letter, let the translated word also start with a lower case letter;
- if a word starts with an upper case letter, let the translated word also start with an upper case letter;
- upper and lower cases should be preserved. For example, `a DOG` should be translated as `een HOND`

[bkiers]

Note that this first version is pretty much an AI translation! Scrolling through some of the files, I see quite some things not correctly translated. Consider this PR as a draft.

[epoz]

Super! Thanks @bkiers
We will ask the editors to review the work and get back to you.