reworked manifest handling

- manifest files wont be created unless symbols are resolved
- delay mt.exe presence check until we launch it
- create explicit case that writes manifests to disk
- moved manifest dependency collection step to happen after obj input
- removed /rad_delete_manifest

src/linker/lnk_obj.h

@@ -151,7 +151,7 @@ typedef struct
 
 typedef struct
 {
-  LNK_Obj     **in_arr;
+  LNK_ObjNode  *in_arr;
   String8List  *out_arr;
   Rng1U64      *range_arr;
 } LNK_ManifestDependencyCollector;