Bump bdk version to 0.24.0

[notmandatory]

Description

Update BDK to the latest version, 0.24.0.

Notes to the reviewers

I also had to add base64 as a new dev dependency because it's not exported by bdk.

[notmandatory]

This still has some bugs to fix and can't be merged until after bdk 0.24.0 is released.

[benthecarman]

Looks like the only failing test is just the error message that slightly changed, this should be able to move forward

[notmandatory]

I had to fix a couple things to get tests to pass:

• updated to new Miniscript error string
• according to bitcoin-cli and bip173.org the new PSBT data looks like it added a value for bip32_derivs, otherwise PSBTs are the same, so updated test with new PSBT.

  diff psbt-left.txt psbt-right.txt 
  73,80c73
  <       },
  <       "bip32_derivs": [
  <         {
  <           "pubkey": "032b0558078bec38694a84933d659303e2575dae7e91685911454115bfd64487e3",
  <           "master_fingerprint": "ece52657",
  <           "path": "m"
  <         }
  <       ]
  ---
  >       }

[notmandatory]

I'll make the release now and then we'll get the updatedbdk-cli released too. Thanks for testing it out with your app.