#20·Register ASTR(Astar network) and RING(Darwinia network) assets on SubBridge - motion #20

This motion is a batch call to register the following assets and set corresponding execution price:

1. ASTR: id=6, path="../2006/", sym=ASTR, dec=18, execution price=40x10^18(0.5 * PHAExecutionPrice)
2. RING: id=7, path="../2046/PalletIntance(5)", sym=RING, dec=18, execution price=4000x10^18(50*PHAExecutionPrice)