Update locales and simplifies bw-dev command for loading locales

[mouse-reeve]

Description

The bw-dev script for updating locales used to manually select which files to copy, which is unnecessarily complicated -- this change will load them all wholesale. I have also updated the locale files themselves.

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What type of Pull Request is this?

• Bug Fix
• Enhancement
• Plumbing / Internals / Dependencies
• Refactor

Does this PR change settings or dependencies, or break something?

• This PR changes or adds default settings, configuration, or .env values
• This PR changes or adds dependencies
• This PR introduces other breaking changes

Details of breaking or configuration changes (if any of above checked)

Documentation

• New or amended documentation will be required if this PR is merged
• I have created a matching pull request in the Documentation repository
• I intend to create a matching pull request in the Documentation repository after this PR is merged

Tests

• My changes do not need new tests
• All tests I have added are passing
• I have written tests but need help to make them pass
• I have not written tests and need help to write them

[hughrun]

@mouse-reeve I just want to check my understanding here.

1. Updates happen to translations in Crowdin
2. Crowdin pushes new translations to l10n_main as they are available
3. We run ./bw-dev update_locales whilst in main
   i. All /locale files from l10n_mainare copied into the same folder in the working branch (main)
   ii. Django makes and compiles translations including a en_US reference file
4. We manually make a PR to merge these locales changes into main
5. We pull the PR to update locales
6. There is now a new reference file in en_US
7. Using the changes in the new reference file, updates happen to translations in Crowdin...

Is that right? And if not, what did I get wrong?

[mouse-reeve]

That's exactly the process!