eliminate unnecessary info in debug engine entity abstraction / demon events; adjust symbol server / debug info loading such that the debug info loader is the one who decides to kick off downloads based on presence in cache path; use cache path as key, unpack info for download requests

src/symbol_server/symbol_server.h

@@ -13,7 +13,9 @@ SMSV_Status;
 
 internal void smsv_init(void);
 internal void smsv_async_tick(void);
+internal String8 smsv_cache_path(void);
 internal String8 smsv_local_path_from_key(Arena *arena, String8 dbg_name, Guid guid, U64 age);
+internal void smsv_fill_local_path(String8 path);
 internal SMSV_Status smsv_status_from_local_path(String8 path);
 
 #endif // SYMBOL_SERVER_H

src/symbol_server/symbol_server_stub.c

@@ -11,12 +11,23 @@ smsv_async_tick(void)
 {
 }
 
+internal String8
+smsv_cache_path(void)
+{
+  return s("");
+}
+
 internal String8
 smsv_local_path_from_key(Arena *arena, String8 dbg_name, Guid guid, U64 age)
 {
   return s("");
 }
 
+internal void
+smsv_fill_local_path(String8 path)
+{
+}
+
 internal SMSV_Status
 smsv_status_from_local_path(String8 path)
 {