Decode main_data in decode_wal_record().

Replay XLOG_XACT_COMMIT and XLOG_XACT_ABORT records in walredo.
Don't wait for lsn catchup before walreceiver connected.
Use 'request_nonrel' branch of vendor/postgres

integration_tests/tests/test_pageserver.rs

@@ -3,6 +3,7 @@ use control_plane::compute::ComputeControlPlane;
 use control_plane::local_env;
 use control_plane::local_env::PointInTime;
 use control_plane::storage::TestStorageControlPlane;
+use std::{thread, time};
 
 // XXX: force all redo at the end
 // -- restart + seqscan won't read deleted stuff
@@ -96,6 +97,9 @@ fn test_pageserver_two_timelines() {
     node1.start().unwrap();
     node2.start().unwrap();
 
+    //give walreceiver time to connect
+    thread::sleep(time::Duration::from_secs(3));
+
     // check node1
     node1.safe_psql(
         "postgres",