Complete empty square brackets of proses

[Dropries]

Change description

This is a large stylistic PR that aims to ensure that the API return proses in a single language. When a prose contains []{a:b}, this pattern is replaced by b, which exists only in English, resulting in sentences mixing foreign languages and a single English word b.

In each data/v2/csv/~_prose.csv file, I replaced all empty square brackets of the form []{a:b} by [c]{a:b} where c is obtained from the data/v2/csv/a_names.csv file based on the local_language_id of the prose.

A few German []{mechanic:b} are still empty because there is no file containing the translation of mechanics and I don't really know German...

AI coding assistance disclosure

None

Contributor check list

• I have written a description of the contribution and explained its motivation.
• I have written tests for my code changes (if applicable).
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