Remove all checked in *.wasm files to the repo (#563)

* Tidy up the `hello` example for `wasmtime`

* Remove the `*.wat` and `*.wasm` files and instead just inline the
  `*.wat` into the example.

* Touch up comments so they're not just a repeat of the `println!`
  below.

* Move `*.wat` for `memory` example inline

No need to handle auxiliary files with the ability to parse it inline!

* Move `multi.wasm` inline into `multi.rs` example

* Move `*.wasm` for gcd example inline

* Move `*.wat` inline with `import_calling_export` test

* Remove checked in `lightbeam/test.wasm`

Instead move the `*.wat` into the source and parse it into wasm there.

* Run rustfmt

crates/lightbeam/src/module.rs

@@ -9,6 +9,7 @@ use cranelift_codegen::{
 };
 use memoffset::offset_of;
 use more_asserts::assert_le;
+use thiserror::Error;
 use wasmparser::{FuncType, MemoryType, ModuleReader, SectionCode, Type};
 
 pub trait AsValueType {
@@ -133,9 +134,11 @@ impl TranslatedModule {
     }
 }
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Error)]
 pub enum ExecutionError {
+    #[error("function index out of bounds")]
     FuncIndexOutOfBounds,
+    #[error("type mismatch")]
     TypeMismatch,
 }