feat(models): Added Extractor class

Extractor extracts data from responses:
- Supports JSON path extraction
- Supports header and status extraction
- Saves extracted values to Context

models/extractor.py

@@ -0,0 +1,31 @@
+from typing import Any
+from .context import Context
+from .itm import ExtractModel
+from .executor import Response
+
+
+class Extractor:
+    def __init__(self, context: Context):
+        self.context = context
+
+    def extract(self, configs: list[ExtractModel], response: Response):
+        for config in configs:
+            value = self._get_value(response, config)
+            self.context.set_extracted(config.name, value)
+
+    def _get_value(self, response: Response, config: ExtractModel) -> Any:
+        if config.source == "status":
+            return response.status
+        if config.source == "header":
+            return response.headers.get(config.json_path)
+        return self._json_path(response.body, config.json_path)
+
+    def _json_path(self, data: dict, path: str) -> Any:
+        parts = path.lstrip("$.").split(".")
+        current = data
+        for part in parts:
+            if isinstance(current, dict):
+                current = current.get(part)
+            else:
+                return None
+        return current