Add support for client-side localisation

[Badgerati]

Pode currently has support for localisation on server-side strings - primarily errors and some informational text displayed on the terminal.

This will include the other side to this, which is to allow localised values - strings, dates, times, numbers - but for the client-side.

The plan is to leverage the AutoImport feature, which will automatically import any locale files found in a /locales folder found at the root of your server - similar to /views. The path can be customised, or the auto-importing disabled. And there will also be an Import-PodeLocaleData to do this manually, as well as an Add-PodeLocale to fully do it programmatically via a hashtable.

The structure of the folder will be the same as what Import-LocalizedData expects - where sub-directories are the names of the locales/cultures, and they then each contain .psd1 files.

/locales
    /en
        /Locales1.psd1
        /Locales2.psd1
    /fr
        /Locales1.psd1
        /Locales2.psd1

During a web request, Pode will automatically calculate which culture the request should use via:

• Cookies - such as pode.culture
• Headers - such as X-PODE-CULTURE
• Session (such as $WebEvent.Session.Data.Culture)
• Authenticated User (such as $WebEvent.Auth.User.Culture)
• Accept-Language header
• Server default culture - either custom or from $PSUICulture
• en

There will also be new scoped variables to help:

• $locale:
• $datetime:
• $date:
• $time:
• $number:

The latter ones for datetimes and numbers will help localise variables containing datetimes/numbers.