Refactor paths and runtime names (#507)

chore: refactor for consistant naming of the crates and paths of the runtimes

* tests: ignore folder created by the tests
* chore: refactoring
* Update polkadot-parachains/Cargo.toml

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

polkadot-parachains/statemint/build.rs

@@ -0,0 +1,9 @@
+use substrate_wasm_builder::WasmBuilder;
+
+fn main() {
+	WasmBuilder::new()
+		.with_current_project()
+		.export_heap_base()
+		.import_memory()
+		.build()
+}