Implement multiple languages support for the TermsOfServices

[martinRenou]

Taking over #543 and making some changes in the original implementation.

[wolfv]

@martinRenou for the linter, you can run pre-commit run --all

[martinRenou]

Thanks!

[hbcarlos]

Thanks, @martinRenou! Looks good.
I'm thinking that maybe we should modify the GET api/tos end-point to receive the language as a parameter.

[codecov-commenter]

Codecov Report

Merging #552 (5bdf23f) into main (1d2feb9) will decrease coverage by 0.81%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #552      +/-   ##
==========================================
- Coverage   82.79%   81.97%   -0.82%     
==========================================
  Files          78       78              
  Lines        5964     5971       +7     
==========================================
- Hits         4938     4895      -43     
- Misses       1026     1076      +50     

Impacted Files	Coverage Δ
quetz/tasks/indexing.py	93.42% <100.00%> (+2.20%)	⬆️
quetz/pkgstores.py	42.45% <0.00%> (-11.60%)	⬇️
quetz/main.py	86.16% <0.00%> (+0.05%)	⬆️

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[hbcarlos]

Thanks, @martinRenou!