Revert header usage.

Author: rkistner

cpp/bindings.cpp

@@ -10,7 +10,6 @@
 #include <iostream>
 #include <string>
 #include <vector>
-#include <powersync>
 
 using namespace std;
 using namespace facebook;
@@ -20,6 +19,11 @@ string docPathStr;
 std::shared_ptr<react::CallInvoker> invoker;
 jsi::Runtime *runtime;
 
+extern "C" {
+int sqlite3_powersync_init(sqlite3 *db, char **pzErrMsg,
+                           const sqlite3_api_routines *pApi);
+}
+
 /**
  * This function loads the PowerSync extension into SQLite
  */