refactor: remove sourcePath parameter from wrenInterpret and related module functions

The sourcePath field on ObjModule was redundant since it always matched the module name except for the main script. This change removes the parameter from wrenInterpret, wrenInterpretInModule, and wrenNewModule, and replaces all references to module->sourcePath with module->name in error reporting and debug output.

src/include/wren.h

@@ -181,17 +181,7 @@ void wrenFreeVM(WrenVM* vm);
 void wrenCollectGarbage(WrenVM* vm);
 
 // Runs [source], a string of Wren source code in a new fiber in [vm].
-//
-// [sourcePath] is a string describing where [source] was located, for use in
-// debugging stack traces. It must not be `null`.
-//
-// If it's an empty string, then [source] is considered part of the "core"
-// module. Any module-level names defined in it will be implicitly imported by
-// another other modules. This also means runtime errors in its code will be
-// omitted from stack traces (to avoid confusing users with core library
-// implementation details).
-WrenInterpretResult wrenInterpret(WrenVM* vm, const char* sourcePath,
-                                  const char* source);
+WrenInterpretResult wrenInterpret(WrenVM* vm, const char* source);
 
 // Creates a handle that can be used to invoke a method with [signature] on the
 // object in [module] currently stored in top-level [variable].