Sendpay with blindedpath

[Lagrang3]

Add extra arguments to sendpay to handle bolt12's blinded paths.

[Lagrang3]

There are some files autogenerated after I hit make:

	modified:   .msggen.json
	modified:   cln-grpc/proto/node.proto
	modified:   cln-grpc/src/convert.rs
	modified:   cln-rpc/src/model.rs
	modified:   contrib/msggen/msggen/schema.json
	modified:   contrib/pyln-grpc-proto/pyln/grpc/node_pb2.py
	modified:   contrib/pyln-grpc-proto/pyln/grpc/node_pb2_grpc.py
	modified:   contrib/pyln-grpc-proto/pyln/grpc/primitives_pb2.py
	modified:   doc/index.rst

some of which are related to my changes, but others are not. I don't know if I should commit them too.

[Lagrang3]

I had a mistake in the schema, rebased on top of that commit.

[daywalker90]

doc/index.rst looks new to me but i think that's ok. Rest is business as usual if you change something in the schema.

[Lagrang3]

Related to #6609.

[Lagrang3]

I am going to archive this for the moment. A new way of making payments has come out with injectpaymentonion and xpay is already using it.