At wallet loading, we rely on chain state querying to retrieve
height of txn, to do so we ensure that lock order is respected
between cs_main and cs_wallet.
If wallet loaded is the wallet-tool one, all wallet txn will
show up with a height of zero. It doesn't matter as confirmation
height is not used by wallet-tool.
Reorder arguments and document Confirmation calls to avoid
ambiguity.
Fixes nits left from #16624
https://github.com/bitcoin/bitcoin/pull/15931/commits/5971d3848e09abf571e5308185275296127efca4
Depends on D7508
Partial backport of Core PR15931