Simplify solana contract stub

[volovyks]

There is no way to remove the contract, but I've managed to remove the additional workspace and 70% of the setup. Now it's a simple Rust project with a single dependency.

[ChaoticTempest]

Are you sure this is no longer needed? Also looks like we're missing

[lib]
crate-type = ["cdylib", "lib"]

[volovyks]

Looks like [lib] was enough to fix the build

[volovyks]

@ChaoticTempest any blockers on this one?

[ChaoticTempest]

how are we building this contract? I don't see any instructions to do this? I'm trying anchor build inside contract-sol but getting:

thread 'main' panicked at cli/src/lib.rs:1367:47:
Not in workspace.
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

[volovyks]

@ChaoticTempest
It is getting built with cargo build as a part of our workspace.
Compiling signet-program v0.1.0 (/Users/serhii/Projects/mpc/chain-signatures/contract-sol)

Also, you can build it with cargo build inside of the /chain-signatures/contract-sol, since it is a regular rust crate now, no Anchor framework anymore.

Again, this is not a real contract, this is just a way to provide structs for our sol rpc.