Type and naming cleanup

Do not use Hi prefic for things that shouldn't be visible to outside code

test/manual/minimal.cpp

@@ -24,7 +24,7 @@ int main(int argc, char *argv[]) {
     printf("otherValue: %d\n", minimal_lib::otherValue++);
     std::this_thread::sleep_for(std::chrono::seconds(1));
 
-    if (hi_reload() != HILOAD_OK) {
+    if (hi_reload() != HI_OK) {
       fprintf(stderr, "Failed to load modules\n");
     }
   }