CLEANUP: h1-htx: Move htx-to-h1 formatting functions from htx.c to h1_htx.c

The functions "htx_*_to_h1()" have been renamed into "h1_format_htx_*()" and
moved in the file h1_htx.c. It is the right place for such functions.
diff --git a/include/proto/h1_htx.h b/include/proto/h1_htx.h
index 51db02c..e77663b 100644
--- a/include/proto/h1_htx.h
+++ b/include/proto/h1_htx.h
@@ -35,6 +35,11 @@
 int h1_parse_msg_tlrs(struct h1m *h1m, struct htx *dsthtx,
 		      struct buffer *srcbuf, size_t ofs, size_t max);
 
+int h1_format_htx_reqline(const struct htx_sl *sl, struct buffer *chk);
+int h1_format_htx_stline(const struct htx_sl *sl, struct buffer *chk);
+int h1_format_htx_hdr(const struct ist n, const struct ist v, struct buffer *chk);
+int h1_format_htx_data(const struct ist data, struct buffer *chk, int chunked);
+
 #endif /* _PROTO_H1_HTX_H */
 
 /*