Update json format for bid psbt errors

[buffrr]

Should look like this concatenated instead of the separate "bid_psbt_reason" field which looked inconsistent with rejects vs revokes

reject

{
  "n": 1,
  "script_error": {
    "type": "reject",
    "name": "@tap4",
    "reason": "bid_psbt_output_spent"
  }
}

revoke

{
  "type": "revoke",
  "reason": "bid_psbt_output_spent",
  "output": {
    "txid": "ef1c24f8384fbf7f0a7e9da88a25ee5e45e3a87e7032abd682171a3f545ee26d",
    "n": 1,
    "name": "@town",
    "covenant": {
      "type": "bid",
      "burn_increment": 1000,
      "signature": "594f7132b6a0b13654f440e85dcc8d676c768b3a485446b60fa44389a26dff721b13c148a0e4d39cf530efad86cba295329d5571c42fd46e1ccf81e015d86400",
      "total_burned": 1000,
      "claim_height": 50833
    },
    "value": 662,
    "script_pubkey": "5120eef9e4b2a75e2c01c79b80faf79b763bda9aae953621fdf97bcbae490e38e64f"
  }
}

revoke non bid psbt error

{
  "type": "revoke",
  "reason": "premature_claim",
  "output": {
    "txid": "be3386da6ebb1c036ec8b0d28b52cfd38bc23e442642a1a8b73f16466391ee61",
    "n": 1,
    "name": "@tap3",
    "covenant": {
      "type": "bid",
      "burn_increment": 1000,
      "signature": "d34f49ee2fe69c82aff08252c0e6f83adc318297250c5d0d4a9edc8032cfbe009893c8a900d8e5a2d8778641885d2b6ca633876af5a4d3522069225c95f5fbc5",
      "total_burned": 1000,
      "claim_height": null
    },
    "value": 662,
    "script_pubkey": "5120ebe2a13988500badbb1268a18b5954604baef384a8291cf0c361df2437cb7ea7"
  }
}