Send translated emails in the same language the commerce module would send

I have updated patch for latest version 1.0.0 of the module.

Small notice. Mine patch is incompatible with this issue: https://www.drupal.org/project/commerce_email/issues/3314082 🐛 Mail "to" replaceTokens Fixed . Anyway the metioned issue is resolved also.

I have updated the patch for the latest dev branch changes. There is the same feature request that is not dependent on the commerce core patch ( https://www.drupal.org/project/commerce_email/issues/3282118 → ). Definitely, there is demand for this feature.

Fix the error in patch from previous comment.

I also need this functionality, didn't expect that it would not be standard...

Attached is a revised patch that works against latest stable release. (8.x-1.5)

I've added 2 changes:
1/ passing the langcode also to the the $params array
2/ reset the active language to what it was after the mail processing; this would prevent any other processes from using the wrong language

Also fixed som typos in variable names. (but that might be because of changes to dev?)

I als think this still needs work since the behaviour should be optional/configurable.
You do not always want to send mails in the customers language. For example when sending mails to administrators, they prefer fixed language.