feat: publish issuer/brand under arbitrary name

[dckc]

fixes #10

story: Larry needs a way for people to make smart wallet offers to trade in the new BRD token he's launching (get it? 🏀 ). So he offers 100 IST to the arbAssetName contract to add BRD to agoricNames; it tells him (in the offer result) that the name there is board0371.

~/projects/ag-power-tools/contract$ TRACK_TURNS=enabled DEBUG=track-turns yarn test test/test-arbAssetNames.js
...
  ✔ launcher Larry publishes his asset type 
...
    ℹ publish bundle arbAssetNames b1-d7fc9
    ℹ instance arbAssetName: new Promise
    ℹ instance arbAssetName settled; remaining: []
    ℹ Object @Alleged: InstanceHandle {}
    ℹ Larry launched {
        brand: Object @Alleged: BRD brand {},
        issuer: Object @Alleged: BRD issuer {},
      }
    ℹ Larry offers {
        brand: Object @Alleged: ZDEFAULT brand {},
        value: 100000000n,
      } to publish
    ℹ Larry published as board0371
    ℹ Object @Alleged: BRD brand {} at board0371

[dckc]

good progress:

story: Larry needs a way for people to make smart wallet offers to trade in the new BRD token he's launching (get it? 🏀 ). So he uses the arbAssetName contract to add BRD to agoricNames; it tells him the name there is board0371.

~/projects/ag-power-tools/contract$ TRACK_TURNS=enabled DEBUG=track-turns yarn test test/test-arbAssetNames.js
...
  ✔ launcher Larry publishes his asset type 
...
    ℹ publish bundle arbAssetNames b1-d7fc9
    ℹ instance arbAssetName: new Promise
    ℹ instance arbAssetName settled; remaining: []
    ℹ Object @Alleged: InstanceHandle {}
    ℹ Larry launched {
        brand: Object @Alleged: BRD brand {},
        issuer: Object @Alleged: BRD issuer {},
      }
    ℹ Larry offers {
        brand: Object @Alleged: ZDEFAULT brand {},
        value: 100000000n,
      } to publish
    ℹ Larry published as board0371
    ℹ Object @Alleged: BRD brand {} at board0371