Clean up things that include script/standard.h

Remove standard.h from files that don't use anything in it, and include
it in files that do.

src/script/miniscript.cpp

@@ -5,7 +5,6 @@
 #include <string>
 #include <vector>
 #include <script/script.h>
-#include <script/standard.h>
 #include <script/miniscript.h>
 
 #include <assert.h>

src/script/sign.h

@@ -12,7 +12,6 @@
 #include <pubkey.h>
 #include <script/interpreter.h>
 #include <script/keyorigin.h>
-#include <script/standard.h>
 #include <script/signingprovider.h>
 #include <uint256.h>
 

src/script/signingprovider.cpp

@@ -6,7 +6,6 @@
 #include <script/keyorigin.h>
 #include <script/interpreter.h>
 #include <script/signingprovider.h>
-#include <script/standard.h>
 
 #include <logging.h>
 

src/script/signingprovider.h

@@ -12,7 +12,6 @@
 #include <pubkey.h>
 #include <script/keyorigin.h>
 #include <script/script.h>
-#include <script/standard.h>
 #include <sync.h>
 
 struct ShortestVectorFirstComparator