"Run the numbers" shall use muhash

[carnhofdaki]

Describe the bug Or it should be at least possible to set muhash when calling gettxoutsetinfo. Using the coinstatsindex make it take a second instead of minutes.

To Reproduce Steps to reproduce the behavior:

1. Go to http://127.0.0.1:25441/wallets/wallet/<name_of_wallet>/receive/
2. Click on 'Run the numbers!'
3. It takes too long since running gettxoutsetinfo without muhash parameter is very slow. With muhash parameter, one has to have the small (currently 131MB) coinstatsindex.

Expected behavior "Run the numbers" should take less than a second. It should be immediate.

$ time bitcoin-cli gettxoutsetinfo muhash
{
  "height": 775192,
  "bestblock": "000000000000000000071fafcd59fb89454864d51afc206559111381b22cb630",
  "txouts": 83747992,
  "bogosize": 6243049379,
  "muhash": "fae547fb57efe29fcb36c9caf39114543c5d827d8b0831147ad0f0136dc90a22",
  "total_amount": 19282240.19258451,
  "total_unspendable_amount": 216.05741549,
  "block_info": {
    "prevout_spent": 6465.64625252,
    "coinbase": 6.41212171,
    "new_outputs_ex_coinbase": 6465.48413081,
    "unspendable": 0.00000000,
    "unspendables": {
      "genesis_block": 0.00000000,
      "bip30": 0.00000000,
      "scripts": 0.00000000,
      "unclaimed_rewards": 0.00000000
    }
  }
}
    0m00.02s real     0m00.00s user     0m00.00s system

Desktop (please complete the following information):

• Where is your node running: local full node (plain Bitcoin Core on Linux, no bundles)
• Where is your specter running: pip3 local Linux x86_64
• Browser Chrome
• Specter Version 1.14.5