[Tooling] Add GlotPress integration for Fluent localization files

[iangmaia]

Related:

• Fixes AINFRA-684: Integrate new release-toolkit actions into wordpress-rs

What does it do?

This PR integrates the new Fluent-to-PO conversion actions from release-toolkit to enable a complete translation workflow between the project's Fluent localization files (.ftl) and GlotPress, allowing for:

• Source generation: Converts the source English Fluent file to PO format (.pot) for uploading to GlotPress
• Translation sync: Downloads translated PO files from GlotPress and converts them back to Fluent format, adding them to the project
• Locale management: Supports MAG16 locales with mapping between GlotPress and project locale codes; this was implemented just to limit the languages we know we support, but this mapping can be easily updated in the future

Key new lanes

• generate_source_po_file lane - Converts en-US/main.ftl to en-US.pot for GlotPress upload
• download_translations lane - Downloads all available translations from GlotPress following the supported locales list and updates local Fluent files
• generate_fluent_file_from_po lane - Converts individual PO files back to Fluent format
• download_po_files_from_glotpress lane - Downloads PO files for all supported locales

Localization workflow

A day-to-day workflow, to be automated in the next PRs, could work like this (suggestions are welcome):

1. New features are implemented, new localization strings need to be created (or updated)
2. Developers add strings to the source language file wp_localization/localization/en-US/main.ftl.
3. With a certain frequency or based on a trigger (e.g. merge to trunk? A daily scheduled build?), we run generate_source_po_file and commit the updated wp_localization/glotpress/en-US.pot.
4. A wpcom job uploads the updated en-US source file to GlotPress (see 184627-ghe-Automattic/wpcom )
5. Again with a given frequency, we fetch the translations, generate the Fluent files and commit them to the project (or create a PR for review) by running download_translations.

[AliSoftware]

🎗️ Just adding a comment here to serve as a reminder to not merge this PR until we'll have a new version of the release-toolkit shipped and this Gemfile updated to point to it.

[AliSoftware]

I'd suggest to use Dir.mktmpdir do |download_dir| … end instead, not only because this is more idiomatic Ruby when we need a temp dir, but also to guarantee that the temp folder being cleared and deleted once the job is done, and thus that any subsequent runs won't accidentally use a previously downloaded file left over from a previous run.

[AliSoftware]

This is far from idiomatic Ruby, requires shelling out, and is not secure (especially it's vulnerable to command injections).

There are better methods in Ruby to download files from an URI. For example, something like this should work I think:

require 'open-uri'
File.write(po_file_path, URI.open(download_url).read)

[iangmaia]

Moved PR back to Draft after a few discussions with @AliSoftware about the actions generating / parsing the intermediate files and possible alternatives.
This PR and the overall process is still valid and perhaps won't change much regardless of the parsing / generation approach.

[iangmaia]

This PR is superseded by #765