"Create file" and "Create folder" buttons in file pane should not create items, only queue them to be made if name form is submitted

[franknoirot]

Currently, clicking these buttons in the file pane UI immediately creates a new file or folder with the name "Untitled" and an index suffix, then sets that new item to be in "renaming mode" so you can immediately set its name.

Instead, we should follow the example of VS Code. Clicking those buttons opens a UI form to set its name, and if you submit this form the file or folder is then created. If you cancel with Esc or by blurring focus on the input no file system access occurs.

This should include an Electron E2E test or Vitest component test of the behavior.

[franknoirot]

Duplicate of #3248