Support for translations in resource bundle files (.properties)

Hi, would you be open to add support for providing ember-intl translations via a resource bundle files?

If ember-intl does this, editors like intellij provide an improved editor for translating keys:

It works if the editor finds suffixed .properties files in a directory. It’ll merge them into a resource bundle and use a special editor for editing.

From what i can tell it should be possible to support these as the format is very similar to the yaml/json that ember-intl already supports.

The only open question would be how ember-intl detects the locale properties file. As far as I can tell, intellij requires the format .*_[a-z].properties.

One could solve this by transforming any properties file, using a locale suffix, into a JSON translation:

- i18n_de.properties
- i18n_en.properties

This could cause issues if a user creates multiple files with the same suffix, e.g.

- app_de.properties
- shop_engine_de.properties

One could solve this by requiring a specific prefix for each properties file or maybe add a feature to merge multiple translations in the same language.

[Turbo87]

I’ll look into it when I’m back from vacation 😃

[jasonmit]

@RuslanZavacky example of the hook: https://github.com/ember-intl/ember-intl/issues/1464#issuecomment-734009962