PatchEngine: Make PatchType an enum class

Makes the enum strongly typed. A function for retrieving the string
representation of the enum is also added, which allows hiding the array
that contains all of the strings from view (i.e. we operate on the API,
not the exposed internals). This also allows us to bounds check any
querying for the strings.

Source/Core/DolphinWX/ISOProperties/ISOProperties.cpp

@@ -755,9 +755,10 @@ void CISOProperties::PatchList_Save()
       lines.push_back("$" + p.name);
       for (const PatchEngine::PatchEntry& entry : p.entries)
       {
-        std::string temp = StringFromFormat("0x%08X:%s:0x%08X", entry.address,
-                                            PatchEngine::PatchTypeStrings[entry.type], entry.value);
-        lines.push_back(temp);
+        std::string temp =
+            StringFromFormat("0x%08X:%s:0x%08X", entry.address,
+                             PatchEngine::PatchTypeAsString(entry.type), entry.value);
+        lines.push_back(std::move(temp));
       }
     }
     ++index;