EPUBCFISelector is implemented as CfiSelector in Thorium Desktop reader

[danielweck]

https://github.com/search?q=repo%3Aedrlab%2Fthorium-reader+cfiselector&type=code

https://github.com/readium/annotations/blob/main/Selectors.md#use-the-epub-cfi-selector

https://github.com/readium/annotations/blob/main/Selectors.md#epubcfiselector

[danielweck]

see edrlab/thorium-reader#3709