Implement the Episode translation system

[Wohlstand]

There is already on-going work at the wip-translator branch.

This task replaces the obsolete issue #284 which had a different idea.

Implement the technology that will allow making non-destructable translations for episodes. This idea exists for a long time, and now it's a time to finally implement it.

TheXTech-side work:

• Localisation system to translate game into other languages TheXTech/TheXTech#494
• Episodes localization and translation system TheXTech/TheXTech#340

Moondust-side work:

Moondust Translator

It's a brand-new component of Moondust Project which allows users making/editing/browsing translations for SMBX episodes.

• Make the internal structure.
• Make the episode data scanner and structure builder, and JSON generator/loader.
• Implement the list of files UI.
• Implement the strings list UI.
• Implement the message preview area.
• Implement the list of dialogue chains.
• Implement the dialogue preview.
• Make the synchronisation when languages gets changed.
• Implement the TR-ID based technology.
• Implement the language manager widget: it should be able to add/remove/show/hide available languages at the episode.
• Make an original language selection when making a new project (i.e. opening an episode that has no translations at all).
• Make the proper indication of the finishing state including making bold/regular fonts:
  • When There is any untranslated stuff, make bold font at the main list.
  • Make the check column state being synchronised with the recently selected language to properly indicate the state.
• Implement the hints list widget that will show similar strings among others at the whole project, including vanished lines. Similar to Qt Linguists's one. Once you click any of these lines, it will be inserted into the current translation field to save the time on duplicated strings translation.
• Make the about dialogue.
• Make own icon for the application.
• Add missing incons for entry types (NPC, event message, world title, etc.).
• Make different ways of previews:
  • when it's a LunaScript message print, show with the coordinates and related stuff.
  • when it's a world title, show it as single line without intendation,
  • etc.

Moondust Engine

• Backport the done episode translation from TheXTech code to the Moondust Engine once the final translation specification will be commited.

[LoveBodhi]

My task is:

• Adding ZH-CN Translation, which is an important task.