pixelbender: Implement assembly

Pixel Bender assembly allows creating Pixel Bender kernels easily with
low level instructions.

Author: kjarosh

Cargo.lock

@@ -15,3 +15,9 @@ thiserror = { workspace = true }
 num-traits = { workspace = true }
 num-derive = { workspace = true }
 byteorder = { workspace = true }
+pest = { version = "2.8.1", optional = true }
+pest_derive = { version = "2.8.1", optional = true }
+serde_json = { version = "1.0.140", optional = true }
+
+[features]
+assembly = ["dep:pest", "dep:pest_derive", "dep:serde_json"]