Make PineconeHandler market_specific

[gabrielfior]

Right now we only store OmenMarkets on PineconeHandler, using index

prediction-market-agent/prediction_market_agent/db/pinecone_handler.py

Line 24 in 4817ec6

INDEX_NAME = "omen-index-text-embeddings-3-large"

This is not optimal to agents that receive market_type as parameter, leading to constructs like issue, which we don't want.

To be implemented on PineconeHandler:
-> add method get_market_by_id to AgentMarket
-> create a dict or Enum for retrieving index_name for market_type (on PineconeHandler)
-> add check to method to make sure index exists, else throw error