Support with_localizations query string for Get Application Commands endpoints

[EliasStar]

The endpoints "Get Global Application Commands" and "Get Guild Application Commands", which are implemented in (*Session).ApplicationCommands(string, string), don't return name_localizations and description_localizations by default, as described in the Discord Docs. Instead, those endpoints supply name_localized and description_localized, which only contain one localization based on the request. The full name_localizations and description_localizations can only be obtained by supplying with_localizations=true in the query string.

As far as I know this is not currently possible with DiscordGo. Furthermore name_localized and description_localized aren't accessible with the current ApplicationCommand struct.