Expose per-Vault economic data via notification and RPC

[Tartuffo]

No description provided.

[Tartuffo]

@dckc Please confirm that @dtribble 's assertion that per-Vault Collateral amount and interest amount is available via notification, and close this ticket if it is confirmed.

[dckc]

Yes, it does, as shown in these unit tests:

agoric-sdk/packages/run-protocol/test/vaultFactory/test-vaultFactory.js

Lines 532 to 539 in 12e6194

	let notification = await E(vaultNotifier).getUpdateSince();
	trace(t, 'got notificaation', notification);
	t.is(notification.value.vaultState, Phase.ACTIVE);
	t.deepEqual((await notification.value).debtSnapshot, {
	debt: AmountMath.add(loanAmount, fee),
	interest: makeRatio(100n, runBrand),
	});

agoric-sdk/packages/run-protocol/test/vaultFactory/test-vaultFactory.js

Lines 1456 to 1458 in 12e6194

	let aliceUpdate = await E(aliceNotifier).getUpdateSince();
	t.deepEqual(aliceUpdate.value.debtSnapshot.debt, runDebt);
	t.deepEqual(aliceUpdate.value.locked, collateralAmount);