Merge bitcoin#18027: "PSBT Operations" dialog

931dd47 Make lint-spelling.py happy (Glenn Willen)
11a0ffb [gui] Load PSBT from clipboard (Glenn Willen)
a6cb0b0 [gui] PSBT Operations Dialog (sign & broadcast) (Glenn Willen)
5dd0c03 FillPSBT: report number of inputs signed (or would sign) (Glenn Willen)
9e7b23b Improve TransactionErrorString messages. (Glenn Willen)

Pull request description:

  Add a "PSBT Operations" dialog, reached from the "Load PSBT..." menu item, giving options to sign or broadcast the loaded PSBT as appropriate, as well as copying the result to the clipboard or saving it to a file.

  This is based on Sjors' bitcoin#17509, and depends on that PR going in first. (It effectively replaces the small "load PSBT" dialog from that PR with a more feature-rich one.)

  Some notes:
  * The way I display status information is maybe unusual (a status bar, rather than messageboxes.) I think it's helpful to have the information in it be persistent rather than transitory. But if people dislike it, I would probably move the "current state of the transaction" info to the top line of the main label, and the "what action just happened, and did it succeed" info into a messagebox.
  * I don't really know much about the translation/localization stuff. I put tr() in all the places it seemed like it ought to go. I did not attempt to translate the result of TransactionErrorString (which is shared by GUI and non-GUI code); I don't know if that's correct, but it matches the "error messages in logs should be googleable in English" heuristic. I don't know whether there are things I should be doing to reduce translator effort (like minimizing the total number of distinct message strings I use, or something.)
  * I don't really know how (if?) automated testing is applied to GUI code. I can make a list of PSBTs exercising all the codepaths for manual testing, if that's the right approach. Input appreciated.

ACKs for top commit:
  instagibbs:
    tested ACK bitcoin@931dd47
  Sjors:
    re-tACK 931dd47
  jb55:
    ACK 931dd47
  achow101:
    ACK 931dd47

Tree-SHA512: ade52471a2242f839a8bd6a1fd231443cc4b43bb9c1de3fb5ace7c5eb59eca99b1f2e9f17dfdb4b08d84d91f5fd65677db1433dd03eef51c7774963ef4e2e74f

src/wallet/scriptpubkeyman.cpp

@@ -2239,8 +2239,11 @@ SigningResult DescriptorScriptPubKeyMan::SignMessage(const std::string& message,
     return SigningResult::OK;
 }
 
-TransactionError DescriptorScriptPubKeyMan::FillPSBT(PartiallySignedTransaction& psbtx, int sighash_type, bool sign, bool bip32derivs) const
+TransactionError DescriptorScriptPubKeyMan::FillPSBT(PartiallySignedTransaction& psbtx, int sighash_type, bool sign, bool bip32derivs, int* n_signed) const
 {
+    if (n_signed) {
+        *n_signed = 0;
+    }
     for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) {
         const CTxIn& txin = psbtx.tx->vin[i];
         PSBTInput& input = psbtx.inputs.at(i);
@@ -2285,6 +2288,13 @@ TransactionError DescriptorScriptPubKeyMan::FillPSBT(PartiallySignedTransaction&
         }
 
         SignPSBTInput(HidingSigningProvider(keys.get(), !sign, !bip32derivs), psbtx, i, sighash_type);
+        bool signed_one = PSBTInputSigned(input);
+        if (n_signed && (signed_one || !sign)) {
+            // If sign is false, we assume that we _could_ sign if we get here. This
+            // will never have false negatives; it is hard to tell under what i
+            // circumstances it could have false positives.
+            (*n_signed)++;
+        }
     }
 
     // Fill in the bip32 keypaths and redeemscripts for the outputs so that hardware wallets can identify change

src/wallet/scriptpubkeyman.h

@@ -592,7 +592,7 @@ class DescriptorScriptPubKeyMan : public ScriptPubKeyMan
 
     bool SignTransaction(CMutableTransaction& tx, const std::map<COutPoint, Coin>& coins, int sighash, std::map<int, std::string>& input_errors) const override;
     SigningResult SignMessage(const std::string& message, const PKHash& pkhash, std::string& str_sig) const override;
-    TransactionError FillPSBT(PartiallySignedTransaction& psbt, int sighash_type = 1 /* SIGHASH_ALL */, bool sign = true, bool bip32derivs = false) const override;
+    TransactionError FillPSBT(PartiallySignedTransaction& psbt, int sighash_type = 1 /* SIGHASH_ALL */, bool sign = true, bool bip32derivs = false, int* n_signed = nullptr) const override;
 
     uint256 GetID() const override;