add i18n checker and autogenerated AI translations

[prusnak]

As discussed in #2122, I came up with an i18n checker scripts. As we can see from running it, there are many unmaintained language files with lots of missing and unused strings.

$ python3 tools/i18n-check.py | grep Missing
Missing ids in language "br": 95
Missing ids in language "cn": 64
Missing ids in language "de": 70
Missing ids in language "es": 70
Missing ids in language "fr": 95
Missing ids in language "it": 95
Missing ids in language "jp": 71
Missing ids in language "kr": 2
Missing ids in language "nl": 95
Missing ids in language "pi": 95
Missing ids in language "pl": 95
Missing ids in language "pt": 95
Missing ids in language "we": 95

This PR adds the tools/i18n-check.py tool which is able to detect these unmaintained language files and it also adds another tool tools/i18n-ai-tool.py which uses GPT-4 API to translate missing strings.

This PR also contains several manual fixes as well as translations generated by the AI tool.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (9f835f8) 60.44% compared to head (12825e4) 60.45%.

Additional details and impacted files

@@            Coverage Diff             @@
##              dev    #2160      +/-   ##
==========================================
+ Coverage   60.44%   60.45%   +0.01%     
==========================================
  Files          58       58              
  Lines        8464     8464              
==========================================
+ Hits         5116     5117       +1     
+ Misses       3348     3347       -1     

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[arcbtc]

this is amazing