new reanchor compatible change

[zqhxuyuan]

relates to: paritytech/polkadot#4470

orml: open-web3-stack/open-runtime-module-library#672

[zqhxuyuan]

change CurrencyIdConvert to support canonical reanchor. we only need adapt to-reserve and non-reserve cases. make karura and bifrost as example.

• Karura -> [BNC] -> Bifrost. From Bifrost's point of view, the reanchored location change from (1, Parachain(2001), GeneralKey("BNC")) now to (0, GeneralKey("BNC")). so Bifrost make sure compatibility before Karura upgrade.
• Karura -> [KAR] -> Bifrost. no change, From Bifrost's point of view, the reanchored location keep (1, Parachain(2000), GeneralKey("KAR")).
• Bifrost -> [BNC] -> Karura. no change, From Karura's point of view, the reanchored location keep (1, Parachain(2001), GeneralKey("BNC")).
• Bifrost -> [KAR] -> Karura. From Karura's point of view, the reanchored location change from (1, Parachain(2000), GeneralKey("KAR")) now to (0, GeneralKey("KAR")). so Karura make sure compatibility before Bifrost upgrade.
• Karura <-> [KSM] <-> Bifrost. no change.