Seer - add subgraph to SubgraphHandler

[gabrielfior]

• Check if subgraph contains required functions (e.g. getMarkets, getTradesFromUser, etc) and add them to SubgraphHandler
• If not, deploy new subgraph
• Additional reference - see (https://thegraph.com/explorer/subgraphs/AAA1vYjxwFHzbt6qKwLHNcDSASyr1J1xVViDH8gTMFMR?view=Query&chain=arbitrum-one) for Algebra pools, we might need a different source for all pools for a given (outcomeToken, collateralToken) pair

[kongzii]

Instead of adding seer to OmenSubgraphHandler, I vote for a new class, SeerSubgraphHandler. See this comment for the reasoning; TLDR is that OmenSubgraphHandler is already crowded, and it is hard to tell what's going on.

[gabrielfior]

Agree with SeerSubgraphHandler