Burn funds via cli seems to consume the complete UTXO set

[jorgeantonio21]

Describe the bug
In PR #4655, it was added a burn tari command line instruction. While testing this new feature, via cucumber, it was realized that the command seems to consume the complete UTXO set of a given wallet.

To Reproduce
Steps to reproduce the behavior:

1. Consider the cucumber test in fix: refactor incorrect cucumber test on burn funds via cli  #4679. The given error can be reproduced by running it and checking the actual balance of the wallet.
2. After running the burn command, the wallet available funds are at most 18462.621580T, when they should be 221552.530060T - 201552.500000T = 20000.030060T.
3. Moreover, uncommenting line 69 in WalletCli.features makes the get balance request to fail, upon time out.

[SWvheerden]

We have some problem here, but its not the burn.
Wallet A mines 15 blocks
That means the balance should be : 276940_297_425 uT or 276940 T
Burning 45000_000_000 uT and paying a fee of 710 uT
should mean the wallet must have 231940_296_715 uT or 231940 T left.

The test comes back the end with 166164 T
But looking at the database, the wallet has the last 3 coinbases marked as UnspentMinedUnconfirmed
and the change is still marked as EncumberedToBeReceived

Those funds are not counted towards the balance