Switch from delete file by default to trash file by default (#10875)

TODO:

- [x] Don't immediately seg fault
- [x] Implement for directories 
- [x] Add cmd-delete to remove files
- [ ] ~~Add setting for trash vs. delete~~ You can just use keybindings
to change the behavior.

fixes https://github.com/zed-industries/zed/issues/7228
fixes https://github.com/zed-industries/zed/issues/5094

Release Notes:

- Added a new `project_panel::Trash` action and changed the default
behavior for `backspace` and `delete` in the project panel to send a
file to the systems trash, instead of permanently deleting it
([#7228](https://github.com/zed-industries/zed/issues/7228),
[#5094](https://github.com/zed-industries/zed/issues/5094)). The
original behavior can be restored by adding the following section to
your keybindings:

```json5
[
// ...Other keybindings...
  {
    "context": "ProjectPanel",
    "bindings": {
        "backspace": "project_panel::Delete",
        "delete": "project_panel::Delete",
    }
  }
]

crates/worktree/src/worktree_tests.rs

@@ -1764,7 +1764,7 @@ fn randomly_mutate_worktree(
     match rng.gen_range(0_u32..100) {
         0..=33 if entry.path.as_ref() != Path::new("") => {
             log::info!("deleting entry {:?} ({})", entry.path, entry.id.0);
-            worktree.delete_entry(entry.id, cx).unwrap()
+            worktree.delete_entry(entry.id, false, cx).unwrap()
         }
         ..=66 if entry.path.as_ref() != Path::new("") => {
             let other_entry = snapshot.entries(false).choose(rng).unwrap();