Add more LM wrappers

[dmoka]

We want to add more helper/wrappers extrinsics for our LMs:

TODO:

• finish spec and discuss it with UI team
• if we want to add an optional amount for removing liquidity, otherwise we remove all linked to the positions

TODO: add remove liquidty form omnipool and stablesawp

• add optional field for amount

Here are the new APIs:

Omnipool LM

DONE

add_liquidity_with_limit_and_join_farms(
	origin: OriginFor<T>,
	farm_entries: BoundedVec<(GlobalFarmId, YieldFarmId), T::MaxFarmEntriesPerDeposit>,
	asset: T::AssetId,
	amount: Balance,
	min_shares_limit: Balance,
)

exit_farms_and_remove_liquidity(
	origin: OriginFor<T>,
	deposit_id: DepositId,
	yield_farm_ids: BoundedVec<YieldFarmId, T::MaxFarmEntriesPerDeposit>,
)

exit_farms_and_remove_liquidity_with_limit(
	origin: OriginFor<T>,
	deposit_id: DepositId,
	yield_farm_ids: BoundedVec<YieldFarmId, T::MaxFarmEntriesPerDeposit>,
        min_limit: Balance
)

DONE

///Steps for the behaviour
///1. add proportional liquidty to stableswap, so we get 2pool share token
///2. add this 2pool share token as liquidity to omnipool so we get some shares
///3. enter to farms with these omnipool shares.
add_liquidity_stableswap_omnipool_and_join_farms(
			origin: OriginFor<T>,
                        stable_pool_id: T::AssetId,
			assets: Vec<AssetAmount<T::AssetId>>,
			farm_entries: BoundedVec<(GlobalFarmId, YieldFarmId), T::MaxFarmEntriesPerDeposit>,
)

WON'T BE IMPLEMENTED

///Steps for the behaviour
///1. add liquidty to stableswap, so we get 2pool share token
///2. add this 2pool share token as liquidity to omnipool so we get some shares
///3. enter to farms with these omnipool shares.
add_liquidity_one_asset_stableswap_omnipool_and_join_farms(
			origin: OriginFor<T>,
                        stable_pool_id: T::AssetId,
			asset_id:T::AssetId,
			amount: Balance,
			farm_entries: BoundedVec<(GlobalFarmId, YieldFarmId), T::MaxFarmEntriesPerDeposit>,
)

exit_farms_and_remove_liquidity_omnipool_stableswap

WON'T BE IMPLEMENTED

exit_farms_and_remove_liquidity_one_asset_omnipool_stableswap

XYK LM:

exit_farms_and_remove_liquidity(
			origin: OriginFor<T>,
			deposit_id: DepositId,
			asset_pair: AssetPair,
			farm_entries: BoundedVec<YieldFarmId, T::MaxFarmEntriesPerDeposit>,
)