Port ProtoGalaxy from https://github.com/arnaucube/protogalaxy-poc ad…

…apting it to the current folding-schemes lib

Port ProtoGalaxy initial version from https://github.com/arnaucube/protogalaxy-poc adapting it to the current folding-schemes lib
which is a first iteration that implements the Lagrange-basis version from [ProtoGalaxy](https://eprint.iacr.org/2023/1106) folding scheme.
There are some pending optimizations, but is a first step towards integrating ProtoGalaxy in the library.

Cargo.toml

@@ -30,9 +30,10 @@ tracing = { version = "0.1", default-features = false, features = [ "attributes"
 tracing-subscriber = { version = "0.2" }
 
 [features]
-default = ["parallel", "nova", "hypernova"]
-hypernova=[]
+default = ["parallel", "nova", "hypernova", "protogalaxy"]
 nova=[]
+hypernova=[]
+protogalaxy=[]
 
 parallel = [ 
     "ark-std/parallel", 

src/folding/mod.rs

@@ -3,3 +3,5 @@ pub mod circuits;
 pub mod hypernova;
 #[cfg(feature = "nova")]
 pub mod nova;
+#[cfg(feature = "protogalaxy")]
+pub mod protogalaxy;