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/api/Cargo.toml

@@ -54,6 +54,7 @@ wasmtime-wast = { path = "../wast" }
 wasmtime-wasi = { path = "../wasi" }
 rayon = "1.1"
 file-per-thread-logger = "0.1.1"
+wat = "1.0"
 
 [badges]
 maintenance = { status = "actively-developed" }