[POC]Add the translation string.

[andy840119]

As this PR, it can see that it will create 5 class for the translations, and some of them are duplicated.

Not really sure will it be a good idea or the standard to collect the translations:

• Merge some localization file in a single class, like GeneratorStrings.
• Give them a namespace, like Localisation/Edit/Generator/NoteGeneratorStrings.cs?
• Common string in the sub-folder? Like Localisation/Edit/EditCommonStrings.cs.

[andy840119]

Oops, seems placing the localization class into folder cannot be detected by the localization tool.

dotnet localisation to-resx ./osu.Game.Rulesets.Karaoke/osu.Game.Rulesets.Karaoke.csproj

[andy840119]

• test todo list in the description.

[CloneWith]

Is it possible to put all strings into one class, like Localisation.UIStrings?

Then all string translations can use the same method to be fetched, and duplicate strings would be naturally merged into one string.

[andy840119]

Is it possible to put all strings into one class, like Localisation.UIStrings?

No, because will be hard to manage all the translation.

#1265 (comment)

Here's the rule about how to place the translation designed before, i guess will follow this rule after.