Fix FmOpenInExplorer command

This commit fixes a regression with the FmOpenInExplorerCommand, which
was caused by using the `splitext` function instead of `split`.

Author: deathaxe

commands/open_in_explorer.py

@@ -13,7 +13,7 @@ def run(self, visible_on_platforms=None, paths=None):
             if os.path.isdir(path):
                 self.window.run_command("open_dir", {"dir": path})
             else:
-                dirname, basename = os.path.splitext(path)
+                dirname, basename = os.path.split(path)
                 self.window.run_command(
                     "open_dir", {"dir": dirname, "file": basename},
                 )