Contracts move fixtures to new crate (#2246)

Small PR that introduce a new crate that will host RISC-V & wasm
fixtures for testing pallet-contracts

substrate/frame/contracts/fixtures/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "pallet-contracts-fixtures"
+publish = false
+version = "1.0.0"
+authors.workspace = true
+edition.workspace = true
+license.workspace = true
+description = "Fixtures for testing contracts pallet."
+
+[dependencies]
+wat = "1"
+frame-system = { path = "../../system", default-features = false}
+sp-runtime = { path = "../../../primitives/runtime", default-features = false}
+
+[features]
+default = [ "std" ]
+std = [ "frame-system/std", "sp-runtime/std" ]
+