refactor: Update JSON parsing and schema inflation

- Use `json2.decode[json2.Any]` instead of `json2.raw_decode`
- Add `@[required]` to procedure function signatures
- Improve error handling for missing JSONRPC fields
- Update `encode` to use `prettify: true`
- Add checks for missing schema and content descriptor references

lib/schemas/openrpc/decode.v

@@ -19,7 +19,7 @@ pub fn decode(data string) !OpenRPC {
 	mut object := json.decode(OpenRPC, data) or {
 		return error('Failed to decode json\n=======\n${data}\n===========\n${err}')
 	}
-	data_map := json2.raw_decode(data)!.as_map()
+	data_map := json2.decode[Any](data)!.as_map()
 	if 'components' in data_map {
 		object.components = decode_components(data_map) or {
 			return error('Failed to decode components\n${err}')