Milestone 2: ISO 5598 conversion (multilingual)

[couraudt]

Metanorma PR checklist

• Based on the English version here: https://www.iso.org/obp/ui/en/#iso:std:iso:5598:ed-3:v1:en
• Support document new terminology attributes (gender, grammar type, preferred vs accepted terms, etc)
• Support multi languages

[couraudt]

Added so far:

• <fig>
• <table-wrap>
• <tig> with preferredTerm
• Translated titles in title-wrap

[couraudt]

Recently added:

• <fig-group>
• Images fetching (Images are stored locally, in a temporary folder using the urn as path)
• Parallelize download process (for translated titles & images)

[couraudt]

Some questions, from the milestone description @ronaldtse :

• Where to find example of gender & grammar type?
• What are the other elements to add? What is contained in the etc? :)