global: remove unnecessary includes from headers.

Each header should only include the other headers it needs to compile;
`devtools/reduce-includes.sh */*.h` does this.  The C files then need
additional includes if they don't compile.

And remove the entirely useless wire/onion_wire.h, which only serves to include wire/onion_wiregen.h.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

common/test/run-bolt12-format-string-test.c

@@ -9,6 +9,7 @@
 #include <common/bolt12_merkle.h>
 #include <common/features.h>
 #include <common/setup.h>
+#include <common/utils.h>
 
 /* AUTOGENERATED MOCKS START */
 /* Generated stub for features_unsupported */

common/test/run-bolt12_merkle-json.c

@@ -8,6 +8,7 @@
 #include "../../wire/fromwire.c"
 #include "../../wire/peer_wiregen.c"
 #include "../../wire/tlvstream.c"
+#include <ccan/array_size/array_size.h>
 #include <ccan/tal/grab_file/grab_file.h>
 #include <ccan/tal/path/path.h>
 #include <common/channel_type.h>

common/test/run-cryptomsg.c

@@ -2,6 +2,7 @@
 #include <ccan/str/hex/hex.h>
 #include <common/setup.h>
 #include <common/status.h>
+#include <common/utils.h>
 #include <stdio.h>
 #include <wire/peer_wire.h>
 

common/test/run-json.c

@@ -5,6 +5,7 @@
 #include <ccan/tal/str/str.h>
 #include <common/channel_type.h>
 #include <common/json_filter.h>
+#include <common/sciddir_or_pubkey.h>
 #include <common/setup.h>
 #include <inttypes.h>
 #include <stdio.h>