Self-updates and program list from the repo

Sources.py

@@ -40,6 +40,20 @@ def _Get(Url: str) -> bytes:
         raise SourceError(f"Couldn't reach {Url}: {Error}") from Error
 
 
+def GetBytes(Url: str) -> bytes:
+    return _Get(Url)
+
+
+def GetJson(Url: str):
+    """A JSON API response (e.g. Gitea's latest release), or SourceError."""
+    import json
+
+    try:
+        return json.loads(_Get(Url))
+    except ValueError as Error:
+        raise SourceError(f"{Url} didn't return JSON: {Error}") from Error
+
+
 def _RepoUrl(GitUrl: str) -> str:
     return GitUrl.rstrip("/").removesuffix(".git")