[feat] results: automatically set embedded stream url for video results

Currently, many engines that provide video results call the same
`get_embedded_stream_url` method for setting the `iframe_src`. There
is no value in that because this logic is engine-specific and probably
many video engines forgot to implement this.

With these changes, it's done automatically, so engine implementors
don't have to worry about setting an `iframe_src` (unless the engine
explicitly has a field for it).

searx/result_types/__init__.py

@@ -15,6 +15,7 @@
 __all__ = [
     "Result",
     "MainResult",
+    "LegacyResult",
     "KeyValue",
     "EngineResults",
     "AnswerSet",

searx/result_types/_base.py

@@ -31,6 +31,7 @@ from collections.abc import Callable
 import msgspec
 
 from searx import logger
+from searx.utils import get_embedded_stream_url
 
 log = logger.getChild("result_types")
 
@@ -480,6 +481,7 @@ class LegacyResult(dict[str, t.Any]):
     category: str
     publishedDate: datetime.datetime | None
     pubdate: str = ""
+    iframe_src: str | None
 
     # infobox result
     urls: list[dict[str, str]]
@@ -509,6 +511,7 @@ class LegacyResult(dict[str, t.Any]):
         self["score"] = self.get("score", 0)
         self["category"] = self.get("category", "")
         self["publishedDate"] = self.get("publishedDate")
+        self["iframe_src"] = self.get("iframe_src")
 
         if "infobox" in self:
             self["urls"] = self.get("urls", [])
@@ -531,6 +534,10 @@ class LegacyResult(dict[str, t.Any]):
                 DeprecationWarning,
             )
 
+        # TODO: move into typed video results class once it is implemented  # pylint: disable=fixme
+        if self.template == "videos.html" and self.url and not self.iframe_src:
+            self.iframe_src = get_embedded_stream_url(self.url)
+
     def __getattr__(self, name: str, default: t.Any = UNSET) -> t.Any:
         if default == UNSET and name not in self:
             raise AttributeError(f"LegacyResult object has no field named: {name}")