Rename script/standard.{cpp/h} to script/solver.{cpp/h}

Since script/standard only contains things that are used by the Solver
and its callers, rename the files to script/solver.

src/script/descriptor.cpp

@@ -10,7 +10,7 @@
 #include <script/miniscript.h>
 #include <script/script.h>
 #include <script/signingprovider.h>
-#include <script/standard.h>
+#include <script/solver.h>
 #include <uint256.h>
 
 #include <common/args.h>

src/script/sign.cpp

@@ -13,7 +13,7 @@
 #include <script/miniscript.h>
 #include <script/script.h>
 #include <script/signingprovider.h>
-#include <script/standard.h>
+#include <script/solver.h>
 #include <uint256.h>
 #include <util/translation.h>
 #include <util/vector.h>

src/script/solver.cpp

@@ -3,7 +3,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <script/standard.h>
+#include <script/solver.h>
 #include <pubkey.h>
 #include <script/interpreter.h>
 #include <script/script.h>

src/script/solver.h

@@ -3,8 +3,10 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#ifndef BITCOIN_SCRIPT_STANDARD_H
-#define BITCOIN_SCRIPT_STANDARD_H
+// The Solver functions are used by policy and the wallet, but not consensus.
+
+#ifndef BITCOIN_SCRIPT_SOLVER_H
+#define BITCOIN_SCRIPT_SOLVER_H
 
 #include <attributes.h>
 #include <script/script.h>
@@ -61,4 +63,4 @@ std::optional<std::pair<int, std::vector<Span<const unsigned char>>>> MatchMulti
 /** Generate a multisig script. */
 CScript GetScriptForMultisig(int nRequired, const std::vector<CPubKey>& keys);
 
-#endif // BITCOIN_SCRIPT_STANDARD_H
+#endif // BITCOIN_SCRIPT_SOLVER_H