add FastLP to vbank in initial deployment

[dckc]

What is the Problem Being Solved?

We have discussed adding FastLP to vbank to enable IBC transfer etc. in due course but not initially.
Meanwhile, FastUSDC clients (on master but unreleased) are looking for FastLP balances in .purses of published.wallet.${addr}.current.
When we add FastLP to vbank, the balance updates will no longer go there (the normal cosmos bank module updates are much more efficient; see #3629, #6652, #8564 ). So that would be a breaking change

Description of the Design

Use E(bankManager).addAsset(...) to add FastLP to vbank in the initial fast usdc deployment.

For the cosmos denom: ufastlp
6 decimal places like IST, BLD, USDC, ATOM, etc.

Security Considerations

nothing novel; follows the usual agoric name services architecture to address phishing etc.

those docs should include material on these considerations: #10702

Scaling Considerations

Eliminates a vbank callback to swingset for every Fast USDC balance update at every liquidity provider's address.

Test Plan

Update existing tests to that clients use cosmos bank queries for FastLP.

Upgrade Considerations

Addressing this issue before initial deployment is intended to avoid some major upgrade considerations.