[VS Incentives]: Implement initGaugeInfo helper

[AlpinYukseloglu]

Background

Create test helper initGaugeInfo that initializes internal group gauge info to be used in CreateGauge. All weights should be initialized to zero since they will later be synced by splitting policy using syncGroupGaugeWeights

Suggested Design

// initGaugeInfo takes in a list of pool IDs and a splitting policy and returns a InternalGaugeInfo struct with weights initialized to zero.
func (k Keeper) initGaugeInfo(ctx sdk.Context, poolIds []uint64, splittingPolicy types.SplittingPolicy) (types.InternalGaugeInfo, error) {
}

Acceptance Criteria

• Function is well tested