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/Cargo.toml

@@ -30,6 +30,7 @@ more-asserts = "0.2.1"
 lazy_static = "1.2"
 wat = "1.0.2"
 quickcheck = "0.9.0"
+anyhow = "1.0"
 
 [badges]
 maintenance = { status = "experimental" }