Revert "Delete vendor/ and the route proxy's: the build module fetches the modules, the root image builds with -mod=mod (issue 1305, C6)"

This reverts commit 9c4bf1f08b.

vendor/github.com/jackc/pgx/v5/pgproto3/doc.go

@@ -0,0 +1,11 @@
+// Package pgproto3 is an encoder and decoder of the PostgreSQL wire protocol version 3.
+//
+// The primary interfaces are Frontend and Backend. They correspond to a client and server respectively. Messages are
+// sent with Send (or a specialized Send variant). Messages are automatically buffered to minimize small writes. Call
+// Flush to ensure a message has actually been sent.
+//
+// The Trace method of Frontend and Backend can be used to examine the wire-level message traffic. It outputs in a
+// similar format to the PQtrace function in libpq.
+//
+// See https://www.postgresql.org/docs/current/protocol-message-formats.html for meanings of the different messages.
+package pgproto3