Refactor endpoint types and align Atomic Assets client with API

[includenull]

This change aligns the Atomic Assets client with the upstream eosio-contract-api Atomic Assets namespace.

• Added missing asset query filters to GetAssetsOptions:
  • has_template_buyoffer
  • template_mint
  • min_template_mint
  • max_template_mint
• Added get_collection_schemas(collection_name) for /atomicassets/v1/collections/:collection_name/schemas.
• Added response types for the collection schemas endpoint so the client can decode its lightweight payload correctly.
• Added the missing search filter to GetTemplatesOptions.
• Updated get_template_stats to support both upstream route forms:
  • /atomicassets/v1/templates/:template_id/stats
  • /atomicassets/v1/templates/:collection_name/:template_id/stats
• Updated GetOffersOptions so offer_id and ids are list types, matching upstream boundary handling.
• Added hide_offers support to get_burns.
• Removed misleading client-only options that are not applied by the upstream API:
  • order from GetAccountsOptions
  • order from get_burns
• Corrected boundary ids typing for string-key endpoints so collections, schemas, accounts, and burns use name lists instead of numeric ID lists.
• Added assets back to SchemaObject to match schema responses from the upstream API.
• Relaxed CollectionStats and SchemaStats so assets and burned can be absent when upstream aggregate queries return null.