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/samples/hello.wat

@@ -0,0 +1,4 @@
+(module
+  (func $hello (import "" "hello"))
+  (func (export "run") (call $hello))
+)