• Don't calculate tx fees for PSBTs with invalid money values

In decodepsbt if an invalid amount is seen, don't calculate the fee
but still show the invalid value in the decode.

In analyze psbt, if an invalid amount is seen, set the next step to
be the creator as the creator needs to remake the transaction so that
it is valid.

• psbt: check output index is within bounds before accessing

This is a backport of Core PR17156

Because we only have segwit style UTXO due to our signature algorithm, some checks and test case are not relevent to us.