Initialize the libzim worker

[Jaifroid]

Fixes #929.

Currently there is no code to prevent initialization if the archive is split arbitrarily. I would prefer to be able to test what happens in this scenario.

[Jaifroid]

Seems to initialize properly:

ZIM has fullTextIndex with listed size: 930615296
Instantiating libzim Web Worker...
Calling libzim WebWorker with parameters {action: 'init', files: Array(1)}action: "init"files: [File][[Prototype]]: Object
WebWorker called with action=init
baseZimFileName = wikipedia_es_all_maxi_2022-09.zim
Module["arguments"] = /work/wikipedia_es_all_maxi_2022-09.zim
runtime initialized
archive loaded libzim-wasm.js:2497
wasm initialized libzim-wasm.js:2497

[Jaifroid]

Codefactor warning is on the library file. I've set it to ignore.

[Jaifroid]

When loading a split ZIM with a full text index, we get:

WebWorker called with action=init
baseZimFileName = wikivoyage_en_all_maxi_2022-10.zim
Module["arguments"] = /work/wikivoyage_en_all_maxi_2022-10.zimaa,/work/wikivoyage_en_all_maxi_2022-10.zimab,/work/wikivoyage_en_all_maxi_2022-10.zimac,/work/wikivoyage_en_all_maxi_2022-10.zimad,/work/wikivoyage_en_all_maxi_2022-10.zimae,/work/wikivoyage_en_all_maxi_2022-10.zimaf,/work/wikivoyage_en_all_maxi_2022-10.zimag,/work/wikivoyage_en_all_maxi_2022-10.zimah,/work/wikivoyage_en_all_maxi_2022-10.zimai,/work/wikivoyage_en_all_maxi_2022-10.zimaj,/work/wikivoyage_en_all_maxi_2022-10.zimak,/work/wikivoyage_en_all_maxi_2022-10.zimal,/work/wikivoyage_en_all_maxi_2022-10.zimam,/work/wikivoyage_en_all_maxi_2022-10.ziman,/work/wikivoyage_en_all_maxi_2022-10.zimao
runtime initialized
***Uncaught (in promise) 5539920***

Clearly an exception is being thrown. It doesn't prevent the archive from loading and displaying, but if we can't fix this now, we should work around it by adding split ZIM detection.

[Jaifroid]

We're getting a File System error with split ZIMs:

[Jaifroid]

This is an error quite deep in the virtual file system code. I don't think it is in the scope of this PR. I'll add an issue for it on javascript-libzim, and we need to prevent libzim loading if we have a split archive here for now.