Manage writing system direction in UI (right to left, etc.) V0

Minimal implementation, see next steps in #1305

In arabic texts:

• concordance contexts display are swaped between left and right
• concordance contexts sizes parameters are swaped
• concordance export contexts are swaped between left and right
• cooccurrences contexts parameters are swaped
• text edition should be justified on the right by default

Solution

[1] Add a new ‘writing-system-direction’ import parameter with default value to 'LTR' (Left To Right) :

• en : Writing system direction
• fr : Orientation du système d'écriture

Possible values:

• LTR: text is written from left to right (e.g. occidental languages)
• RTL: text is written from right to left (e.g. arabic, hebrew)

[2] The import parameter becomes the ‘writing-system-direction’ corpus parameter.

Use the writing-system-direction corpus parameter to build text editions

If (writing-system-direction == RTL)

• HTML edition
  • [3] general rendering
    • set CSS: .p 'direction: rtl'

Use the writing-system-direction corpus parameter to display command results

• [5] Concordance

If (writing-system-direction == RTL)

• SWAP the content of the left context with the content of the right context
• justify left context, pivot and right context RIGHT
• [7] Cooccurrences

Validation test

• test the following arabic binary corpus:
  • binary corpus: UDHR-AR-2025-10-16.txm
  • source: https://www.un.org/ar/about-us/universal-declaration-of-human-rights
• set the import parameter field "Writing system direction" to rtl
• do the import
• open the edition
• compute concordances

(from redmine: issue id 1305, created on 2015/04/09 by Serge Heiden)