cryptic "Withdrawal ... failed" diagnostic on withdraw with copyBag value

[dckc]

Describe the bug

This diagnostic from E(purse).withdraw(amt) seems to be trying to tell me the amounts that aren't in the right isGTE relationship, but [copyBag] is indistinguishable from [copyBag] and hence showing them is not very helpful:

Withdrawal of {"brand":"[Alleged: Place brand]","value":"[copyBag]"} failed because the purse only contained {"brand":"[Alleged: Place brand]","value":"[copyBag]"}

To Reproduce

Steps to reproduce the behavior:

1. call makeIssuerKit with AssetKind.COPY_BAG
2. call E(issuer).makeEmptyPurse()
3. call E(pruse).withdraw(AmountMath.make(brand, makeCopyBag([['sword', 1n]])
4. See error above

Expected behavior

Tell me I don't have enough swords. Or just tell me "insufficient funds" and don't try to show the copyBag values.

Additional context

• feat(smart-wallet): trading in well-known non-vbank assets #8071
• Smart wallet equivalent to suggestIssuer(petname, issuerBoardId) #7226