Add the sqlite3_commit_status() API. For querying a connection for (a) the ranges of wal/wal2 frames written after a successful commit, and (b) the conflicting frame following a failed commit of a BEGIN CONCURRENT transaction.

FossilOrigin-Name: 4b08d4dad6b254a342353e3f765066c85cbc5450fe13501665c648627cca21cd

src/btreeInt.h

@@ -364,6 +364,12 @@ struct Btree {
 #ifndef SQLITE_OMIT_SHARED_CACHE
   BtLock lock;       /* Object used to lock page 1 */
 #endif
+#ifndef SQLITE_OMIT_CONCURRENT
+  /* Return values for sqlite3_commit_status() requests:
+  ** SQLITE_COMMIT_FIRSTFRAME, COMMIT_NFRAME.
+  */
+  u32 aCommit[2];
+#endif
 };
 
 /*