Fix bugs and refactor entity architecture

[LeMyst]

Major improvements across the library:

• Refactored entity classes: introduced TermsEntity base class to share labels/descriptions/aliases handling across Item, Property, and MediaInfo, eliminating code duplication.
• Fixed multiple data type bugs: Time parsing now handles years >4 digits; GlobeCoordinate equality no longer mutates values; Snak/Reference equality comparisons properly typed.
• Improved API robustness: added TIMEOUT config support to prevent indefinite hangs; fixed SPARQL query to send in request body (not URL); changed max_retries default from 1000 to 100.
• Fixed error handling: introduced AnonymousEditNotAllowedError for clearer failures; improved login error messages.
• Added new methods: count() on Claims/Qualifiers to distinguish between distinct properties and total items; lexeme_edit_sense helper.
• Fixed integration tests: corrected fixture scope to session-level; updated exception types; fixed docker-compose volume persistence; added PowerShell instructions.
• Fixed API parameter issues: lexeme_edit_sense now uses correct senseId; search_entities properly truncates results and handles strict_language; edit_entity validates type parameter.
• Fixed fastrun caching: replaced lru_cache with per-instance prop_dt_map to avoid stale cache across containers.
• Fixed edge cases: LanguageValue handles None values; Form.grammatical_features setter validates types and replaces instead of accumulating; Claims comparison with unrelated types returns False.