Proto commits in LightningPeach/lpd

These 10 commits are when the Protocol Buffers files have changed:

Commit:2f5d05d
Author:Vladislav Melnik
Committer:Mykola Sakhno

LNP-1790 add server's `BuildInfo`

The documentation is generated from this commit.

Commit:4fa86f4
Author:Vladislav Melnik
Committer:Vladislav Melnik

LNP-1758 export dot on client's side

Commit:5945dfa
Author:Vladislav Melnik
Committer:Vladislav Melnik

LNP-1758 add rpc call: describe graph in dot format

Commit:a0e61f2
Author:Vladislav Melnik

start integrating rust-wallet

Commit:669f19b
Author:Vladislav Melnik

start integrating rust-wallet

Commit:d072f3c
Author:Vladislav Melnik

[LNP-811] Changed crates structure; * rpc/interface crate contains generated code and proto files; * other crates use rpc/interface, other crates should not use both rpc/implementation and rpc/server; * other crates should have `rpc` feature to isolate such code * rpc/implementation crate uses rpc/interface and other crates to collect the implementation; * rpc/server crate uses rpc/implementation it is glue to the system; It is possible to add glue to some other system, it might either use rpc/implementation or provide its own types similarly to present solution.

Commit:bbf3826
Author:Vladislav Melnik

[LNP-811] Added empty method required by lighting-integration

Commit:a48b996
Author:Vladislav Melnik

[LNP-811] Added dummy routing and payment rpc interfaces

Commit:3cb7286
Author:Vladislav Melnik

[LNP-811] Added dummy channel rpc interface

Commit:c88c156
Author:Vladislav Melnik

added rpc server crate and dummy channel service