Deduplicate polkadotXcm pallet calls for xcm #106
Description
We still have duplicated code left for adapters using polkadotXcm pallet methods such as limitedTeleportAssets.
(See also the related comment in PR#105.)
We want to deduplicate the logic similar to how we did for the xTokens pallet. For reference, see the xTokens-helper file.