Added i18n support for SS4

[AndreasL50]

This pull request adds i18n translation functionality, usable with .yml Files in the lang folder as usual.
I've already included the English and German translation files.

And while I was on it, I decided to add title attributes for the last links in the debugging section with the descriptions copied from the official SilverStripe Document.

Changelog:

• Replaced hard coded Text with translation Tags/Methods.
• Made very few adjustments in BetterNavigatorExtension.php to maintain functionality (A few styles broke).
• Added title attributes to the debug links (Copied Descriptions from the URL Variable Tools Document)

[jonom]

Thanks so much @AndreasLang50! Will be great to have i18n in this module. I will take a closer look soon, but one thing that jumps out is that all of the translation entries should be fully namespaced. Currently 3 keys are under JonoM\BetterNavigator\Extension\BetterNavigatorExtension while the rest are simply under BetterNavigator. I'm happy for all of the keys to go under JonoM\BetterNavigator:, I don't think we need to be any more specific than that.

[AndreasL50]

Yeah, you're right, I thought of it as the root scope, therefore not having any namespaces, but they do make a lot of sense.
I've now put all translations into JonoM\BetterNavigator as requested.

[AndreasL50]

@jonom Any updates on this please? Thanks :)

[jonom]

@AndreasLang50 sorry for the delay on this! Have been super busy but it's on my to do list to check this, aiming to test and merge this week.

[AndreasL50]

Alright, thx!

[jonom]

Great work @AndreasLang50, thank you! Sorry for the delay in reviewing. Merged and tagged a 5.1.0 release.

[AndreasL50]

thanks :)