mobile: v2 implementation

[djkazic]

Here's an initial implementation of mobile-v2, which will replace https://github.com/lightninglabs/lightning-terminal/pull/526. This is distinguished from the initial mobile branch proof of concept by:

• Usage of the litd proxy to route requests to subservers
• New terminal entrypoint instead of duplicated logic in bindings.go

There needs to be a refactor and some review around this code, so I am opening it as a draft PR.

Note: java protoc code generation was not compiling for loop.proto, seems like the deprecated field id may be causing protoc to create conflicting implementations of getIdBytes() between the new and old id types. Removing the deprecated id fields in SwapResponse and SwapStatus fixes the issue.