feat(perp): Gracefully handle errors in MsgLiquidate

[Unique-Divine]

Makes the validation checks skip the part of execution that closes a position and sends funds if there's:

• an invalid trading pair
• an non-existent position
• an invalid trader address

Desired use case: If two MsgLiquidate messages are included in the same transaction and one raises an error, the transaction should still succeed (and only liquidate based on the valid message).

[AgentSmithMatrix]

Let's keep this without merging, there are some comments from @godismercilex about it.

[testinginprod]

I think for the sake of simplicity, I would add a new Msg called MsgMultiLiquidate:

message MsgMultiLiquidate {
repeated msgs_liquidate MsgLiquidate = 1;
}

message MsgMultiLiquidateResponse {
   message LiquidationResponse {
     // reports the index of a successful liquidation
      uint64 index = 1;
      MsgLiquidateResponse resp = 2;
   }
   
   repeated LiquidationResponse = 1;
}

At golang level:

func (k Keeper) MultiLiquidate(ctx sdk.Context, m MsgMultiLiquidate) MsgMultiLiquidateResponse {
   var responses []LiquidationResponse
    for index, liquidation := range m.MsgsLiquidate {
        cacheCtx, commit := ctx.CacheContext()
        liquidationResp, err := k.Liquidate(cacheCtx, liquidation)
        if err != nil {
              continue
              // or maybe here we wanna add extra failure events ???
       }
       commit()
       responses = append(responses, LiquidationResponse { Index: index, MsgLiquidateResponse: liquidationResp }
   }
}

[matthiasmatt]

If we add the error in the liquidation response proto that would be nice

[AgentSmithMatrix]

All in then with the MultiLiquidate message.

[NibiruHeisenberg]

Need to think about limiting the number of liquidations per block.