Multilanguage support with Google Assistant

[Baldhor]

Checklist

• [x] I checked for similar existing requests (both open and closed) before posting.
• [x] My request is generic, other users may benefit from it too.

Proposal

Google assistant integration in Home Assistant doesn't support multi language, it is hard coded in english :

        for state in self._supported_states():
            # level synonyms are generated from state names
            # 'armed_away' becomes 'armed away' or 'away'
            level_synonym = [state.replace("_", " ")]
            if state != STATE_ALARM_TRIGGERED:
                level_synonym.append(state.split("_")[1])

            level = {
                "level_name": state,
                "level_values": [{"level_synonym": level_synonym, "lang": "en"}],
            }
            levels.append(level)

I would like to add support for multi language. Alarmo only provide en.json file, so I made a fr.json file in the translation folder.

However, it doesn't cover attributes translation (only the services we can use from automation), and so the usual local translation functions doesn't work. I do not have the knowledge to add such functionnality. But I think it is related to: https://developers.home-assistant.io/docs/internationalization/core/#entity-state-attributes

Additional info

Bascilly, I need to retrieve the "language value" for each of the possible arming level.

    def sync_attributes(self):
        """Return ArmDisarm attributes for a sync request."""
        response = {}
        levels = []
        for state in self._supported_states():
            if state == STATE_ALARM_ARMED_HOME:
                level = {
                    "level_name": state,
                    "level_values": [{"level_synonym": ["Présent"], "lang": "fr"}],
                }
                levels.append(level)

See above, all I need is to retrieve the language for each supported state. It could also be all the language for each state, like : "level_values": [{"level_synonym": ["Présent"], "lang": "fr"}, {"level_synonym": ["Home"], "lang": en"}],

Remark: I found the state_translated funtion, but nowhere a state_attr_translated function, so I'm unsure how to retrieve all the translation of a state's attribute.