frontend: add button to download hidden papers metadata

[heruka-urgyen]

Based on this request

This PR adds a clickable label "download selected" in the report header visible when all papers are shown. Clicking on it prompts to save a json file with the hidden papers metadata.

My main consideration for UX / UI here was simplicity of implementation. Open for further discussion.

[bzz]

Somehow I completely missed this 😱 🤦

Having this JSON allows for subsequent filtering out papers marked as not relevant.

One thing I could not immediately understand is that if it generates the base64 encoded JSON data lazy on click, or in advance, while displaying the component 🤔

[heruka-urgyen]

Hi @bzz. Thanks for getting back to this.

if it generates the base64 encoded JSON data lazy on click, or in advance

In fact, you pointed to a bug. This was fixed so the generated json represents selected papers when download is clicked. I chose to rewrite the history, be aware when pulling.

[bzz]

Awesome! Thank you.

[bzz]

I will get back to #47 then and see what's missing for building a self-contained binary \w the pre-built frontend served from filesystem under /static URL.

[heruka-urgyen]

@bzz fantastic. Thank you. Merging