[supervision] Add settings selector. (#2959)

sw/supervision/python/utils.py

@@ -18,6 +18,12 @@ PAPARAZZI_HOME = os.getenv("PAPARAZZI_HOME", PAPARAZZI_SRC)
 CONF_DIR = os.path.join(PAPARAZZI_HOME, "conf/")
 
 
+def removeprefix(string: str, prefix: str, /) -> str:
+    if string.startswith(prefix):
+        return string[len(prefix):]
+    else:
+        return string[:]
+
 # TODO: make it work with shell program such as vim.
 def edit_file(file_path, prefix=CONF_DIR):
     path = prefix + file_path