[rococo/wococo] create new testing runtime AssetHubRococo full-featured

[bkontur]

Right now we have two "asset hub" parachains on Rococo:

• Rococo Asset Hub (formerly Rockmine)
• Rockmine2

Both of them are deploying runtimes built from asset-hub-kusama runtime code.

Let's create full-featured (asset-conversion, bridging, nfts, ...) runtime version for AH Rococo/Wococo for testing new features before merging them in AssetHubKusama.

TODOs:

• create new runtime AssetHubRococo
• add all features
• reonboard Rockmine
• unboard Rockmine2