Feature/1856 support regex based recommendations

[HerrKrishna]

What's in the PR

• This is a first version just to let you have a look if this is going into the right direction.
• I will add unit tests next

How to test manually

• Setup a new Regex Recommender for the Named Entity Layer, and value feature
• Check the "Always active" box.
• Select the document that I have attached. It contains lemma annotations.
• Add a Named Entity annotation
• Enter a regex
• Now you should get recommendations for all the lemmas that fit your regex.

Bundestag_08-1.zip

[ukp-svc-jenkins]

Can one of the admins verify this patch?

[reckart]

Thanks for the PR. I have had a look at the code and it looks quite interesting. You appear to have the need to show a popup as part of accepting an annotation and that currently seems to work only if INCEpTION is run as a standalone version in a graphical desktop environment. This requirement is something I need to think about - i.e. if/how this can be handled in such a way that it works in a purely browser-based environment.