Polkadot assets on ethereum (#128)

* Register token from polkadot

* Extract AssetRegistrarMetadata

* ReserveTransfer from AssetHub

* Transfer DOT back to AssetHub

* Fix breaking tests

* Fix register token

* Increase dispatch_gas to cover the actual cost for register token

* Add ConvertAssetId to outbound router

* Rename to SendForeignToken

* Update cost

* Move Command.RegisterToken to top level

* Use VersionedLocation for storage

* Use versioned location

* TokenIdOf follow the same pattern as AgentIdOf

* Rename MintToken to TransferNativeToken

* Rename as SendNativeToken

* More refactoring

* Remove AgentExecuteCommand

* Remove TokenExists check

* Update cumulus/parachains/integration-tests/emulated/tests/bridges/bridge-hub-rococo/src/tests/snowbridge.rs

Co-authored-by: Clara van Staden <[email protected]>

* Benchmark register_token

* More checks for the events

* More tests for send native token

* More tests describe tokenID

* More asset identifiers

* Add LocationToToken & Always use VersionedLocation

* Fix breaking tests

* Update gas cost for registering polkadot token

* Add AgentExecuteCommand back for compatibility

* Split into 2 tests each covers one direction

* Revert the change on AH

* Switch to native token on penpal for the integration

* Make fee asset as configuration parameter of the Channel

* Revert fee_asset_id as channel property

* Short epoch

* Fix integration tests

* Fix format

* Cleanup

* Register relay token

* Use relay token as fee asset

* Fix clippy

* Fix missing dependency

* Remove reanchored prefix from asset_id

* Fix test

* Fix the instruction

* Fix test

* Multi hop transfer

* Fix tests

* allow bridge hub assets

* Register token from BH directly and remove force_register_token

* Decrease gas estimation for PNA

* Cleanup

* Store Location rather than VersionedLocation

* Fix test

* Add more tests

* Revamp reanchor logic

* Improve reanchor & Fix tests

* Use secondary governance channel to register PNA

* Rename as asset location

* Use BoundVec limit size of name&symbol

* Describe location of PNA & more tests

* Add test

* Fix taplo

* More tests

* Cleanup

* Format code

* Batch rename token command

* Remove agent_id

* Rename as AssetMetadata

* Add test for penpal native token

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Co-authored-by: Clara van Staden <[email protected]>
Co-authored-by: Alistair Singh <[email protected]>