open picker (#14524)

Release Notes:

- linux: Added a fallback Open picker for when XDG is not working
- Added a new setting `use_system_path_prompts` (default true) that can
be disabled to use Zed's builtin keyboard-driven prompts.

---------

Co-authored-by: Max <max@zed.dev>

assets/keymaps/default-linux.json

@@ -19,7 +19,6 @@
       "escape": "menu::Cancel",
       "ctrl-escape": "menu::Cancel",
       "ctrl-c": "menu::Cancel",
-      "shift-enter": "picker::UseSelectedQuery",
       "alt-enter": ["picker::ConfirmInput", { "secondary": false }],
       "ctrl-alt-enter": ["picker::ConfirmInput", { "secondary": true }],
       "ctrl-shift-w": "workspace::CloseWindow",
@@ -567,6 +566,13 @@
       "tab": "channel_modal::ToggleMode"
     }
   },
+  {
+    "context": "Picker > Editor",
+    "bindings": {
+      "tab": "picker::ConfirmCompletion",
+      "alt-enter": ["picker::ConfirmInput", { "secondary": false }]
+    }
+  },
   {
     "context": "ChannelModal > Picker > Editor",
     "bindings": {