Update glossary handling to match new multilingual glossary/ dictionary structure introduced by DeepL

Problem/Motivation

DeepL released the v3 endpoint for its glossary functionality and changed the handling of glossaries. The data structure was changed, so that a single glossary can include multiple dictionaries with a given language combination and its entries.

Further information can be found here: https://github.com/DeepLcom/deepl-php?tab=readme-ov-file#glossaries
By releasing the new endpoint, they also reduced the available glossaries for free users to only 1. This major change can be overcome by having multiple dictionaries within the glossary.

Proposed resolution

• follow the migration guide and rewrite the exisiting DeeplGlossaryApi methods
• introduce dictionaries as new entity, which are now part of a multilingual glossary
• handling for free/ pro accounts
  • free users cannot add more than one glossary
  • pro users can add up to 1000 glossaries
• update sync functionality to create glossary/ dictionaries
  • free accounts: in case of having multiple glossaries for a given language combinations those should be merged into a single dictionary
  • pro account: multiple glossaries will be synced as usual - but contain a single dictionary with its entries
  • update general creation workflow for glossaries and dictionaries

User interface changes

• update listing of glossaries and show number of dictionaries within the glossary
• add listing of dictionaries for a given glossary
• add simple search functionality within a dictionary

Data model changes

• deprecate existing entity type deepl_glossary and related functionality
• introduce new entity type DeeplMultilingualGlossary
• introduce new entity type DeeplMultilingualGlossaryDictionary
• add related functionality (forms, views integration, etc..)