Refactor salvage_actor::cut_up (#58414)

* Refactor cut_up

Move mat_set outside of the loop
Invert if
Remove useless braces

* Move uniform distribution into own function

* Refactor into lambdas

Efficiency is calculated once and assigned to a const
The recipe is found in a separate function, more clearly separating that
functionality from what should be done if no recipe is found

* Move find_recipe into own function

* Commenting + renaming

* Hide cut_up and unify try_to_cut and valid_to_cut

* Remove cutter item from cut_up

* Remove one const from function declaration

* Rebalance fab skill, update comments

Fab skill now has a more severe effect but is completely eliminated at
lvl 5

* Unsalvageable or count_by_charges items unsalavgeable

* Check uncraft before crafting recipes

* Limit mass returned from cut up

* Combine num, efficiency into num_adjusted

* cut_up_comp handles eff, remove extra loop

* Add chance to always salvage smth

* Use items count_by_charges instead of discarding

* Formatting

* Check for salvageable before count_by_charges

* Fix error and always round yields down

* Fix usage of get_wielded_item

src/activity_actor.cpp

@@ -5941,9 +5941,11 @@ void longsalvage_activity_actor::finish( player_activity &act, Character &who )
     }
 
     for( item &it : items ) {
-        if( actor->valid_to_cut_up( it ) ) {
+        // Check first and only if possible attempt it with player char
+        // This suppresses warnings unless it is an item the player wears
+        if( actor->valid_to_cut_up( nullptr, it ) ) {
             item_location item_loc( map_cursor( who.pos() ), &it );
-            actor->cut_up( who, *salvage_tool, item_loc );
+            actor->try_to_cut_up( who, *salvage_tool, item_loc );
             return;
         }
     }

src/game.cpp

@@ -8832,7 +8832,7 @@ void game::butcher()
         if( it->is_corpse() ) {
             corpses.push_back( it );
         } else {
-            if( ( salvage_tool_index != INT_MIN ) && salvage_iuse->valid_to_cut_up( *it ) ) {
+            if( ( salvage_tool_index != INT_MIN ) && salvage_iuse->valid_to_cut_up( nullptr, *it ) ) {
                 salvageables.push_back( it );
             }
             if( u.can_disassemble( *it, crafting_inv ).success() ) {
@@ -9029,12 +9029,12 @@ void game::butcher()
         break;
         case BUTCHER_SALVAGE: {
             if( !salvage_iuse || !salvage_tool ) {
-                debugmsg( "null salve_iuse or salvage_tool" );
+                debugmsg( "null salvage_iuse or salvage_tool" );
             } else {
                 // Pick index of first item in the salvage stack
                 item *const target = &*salvage_stacks[indexer_index].first;
                 item_location item_loc( map_cursor( u.pos() ), target );
-                salvage_iuse->cut_up( u, *salvage_tool, item_loc );
+                salvage_iuse->try_to_cut_up( u, *salvage_tool, item_loc );
             }
         }
         break;

src/game_inventory.cpp

@@ -1870,7 +1870,7 @@ class salvage_inventory_preset: public inventory_selector_preset
         }
 
         bool is_shown( const item_location &loc ) const override {
-            return actor->valid_to_cut_up( *loc.get_item() );
+            return actor->valid_to_cut_up( nullptr, *loc.get_item() );
         }
 
     private:

src/item.cpp

@@ -9928,6 +9928,7 @@ bool item::is_salvageable() const
     if( is_null() ) {
         return false;
     }
+    // None of the materials are salvageable or they turn into the original item
     const std::map<material_id, int> &mats = made_of();
     if( std::none_of( mats.begin(), mats.end(), [this]( const std::pair<material_id, int> &m ) {
     return m.first->salvaged_into().has_value() && m.first->salvaged_into().value() != type->get_id();