feat: Improve usability of manifest types (#124)

- Adds some helper functions for creating a manifest, mostly helpful for
the Rust SDK
- Renames `ManifestWasm` to `Wasm`
- Renames `ManifestMemory` to `MemoryOptions`
- `ManifestWasm` and `ManifestMemory` have been marked as deprecated
- Adds an alias from `MemoryOptions::max_pages` to `MemoryOptions::max`
in serde specification

Co-authored-by: Steve Manuel <steve@dylib.so>

python/tests/test_extism.py

@@ -66,7 +66,7 @@ class TestExtism(unittest.TestCase):
     def _manifest(self):
         wasm = self._count_vowels_wasm()
         hash = hashlib.sha256(wasm).hexdigest()
-        return {"wasm": [{"data": wasm, "hash": hash}], "memory": {"max": 5}}
+        return {"wasm": [{"data": wasm, "hash": hash}], "memory": {"max_pages": 5}}
 
     def _count_vowels_wasm(self):
         path = join(dirname(__file__), "code.wasm")