Update LLM translation context

[ayanaar]

Fully fixes #3204

This PR refactors the LLM translation handling to address the integration of LLM translations with keyboard shortcuts. The following changes have been made:

1. Refactored Translation Context:

   • Updated the TranslationContext.tsx to provide multiple LLM translations and the selected option.
   • Changed the state to store llmTranslations as a dictionary of translations based on characteristics.

2. Updated Keyboard Shortcuts:

   • Modified editFieldShortcuts.ts to correctly handle LLM translations when using Ctrl+Shift+Up/Down shortcuts.
   • Ensured that the correct LLM translation is copied into the editor and the source type is set to gpt-transform.

3. Adjusted Machinery Translation Component:

   • Updated MachineryTranslation.tsx to use the new context structure.
   • Adjusted logic to select the appropriate LLM translation and update sources accordingly.

Please note that this is still a work in progress and is not fully functional yet.