Add WAMR API bindings in Python (#1959)

Before adding the new bindings:
1. Moved wasm-c-api in a subfolder wasmcapi in the package.
2. Adapted the tests to be able to run in this new structure.

New:
1. Added the WAMR API in another folder wamrapi in the same level as wasm-c-api.
2. Created an OOP proposal.
3. Added an example using this proposal.

language-bindings/python/wasm-c-api/tests/context.py

@@ -0,0 +1,13 @@
+# -*- coding: utf-8 -*-
+#!/usr/bin/env python3
+#
+# Copyright (C) 2019 Intel Corporation.  All rights reserved.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+
+import sys
+import os
+
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
+
+import wamr