add ability to filter by item notes (#35617)

* add ability to search through filter by item notes with n:

src/item_search.cpp

@@ -63,6 +63,12 @@ std::function<bool( const item & )> basic_item_filter( std::string filter )
                 }
                 return false;
             };
+        // item notes
+        case 'n':
+            return [filter]( const item & i ) {
+                const std::string note = i.get_var( "item_note" );
+                return !note.empty() && lcmatch( note, filter );
+            };
         // by name
         default:
             return [filter]( const item & a ) {

src/output.cpp

@@ -732,10 +732,10 @@ void draw_item_filter_rules( const catacurses::window &win, int starty, int heig
     }
 
     starty += fold_and_print( win, point( 1, starty ), len, c_white,
-                              _( "Search [c]ategory, [m]aterial, [q]uality or [d]isassembled components:" ) );
+                              _( "Search [c]ategory, [m]aterial, [q]uality, [n]otes or [d]isassembled components:" ) );
     fold_and_print( win, point( 1, starty ), len, c_white,
                     //~ An example of how to filter items based on category or material.
-                    _( "Examples: c:food,m:iron,q:hammering,d:pipe" ) );
+                    _( "Examples: c:food,m:iron,q:hammering,n:toolshelf,d:pipe" ) );
     wrefresh( win );
 }