Feat/88 duplicates

[f-lukas]

https://github.com/Pandora-IsoMemo/iso-app/issues/88

• A new button "detect duplicates" has been added that opens a pop-up where duplicates can be detected and removed from the dataset.

Note: I have commented out the export button for now, as you can simply use the existing button in the app.

[f-lukas]

@arunge Thanks for your feedback.

I have adjusted a few things. I have now set the version back to 23.01.5 because you have merged the other feature in the meantime. Thanks for the hint about the bug. Unfortunately I had to remove the highlighting function, although I liked it. With larger data sets, the coloring does not seem to be performant. I get a JS error in the console. Either the table is not displayed at all or not all rows are colored (like in your screenshot). Therefore I have removed the highlighting.

[arunge]

Just merge updates for Description and News.md into this branch before merging. :slightly_smiling_face: