Create a new untitled file when double clicking the no-tabs editor panel

[xgfone]

• When opening Zed, there is not any tabs.
  

• We maybe double click the empty panel, and create a new untitled file, just like we have executed the command worksapce: new file or pressed the shortcut key Ctrl-N.
  

PS: VS Code has supported the feature, which is fairly useful to open zed and create a temporary file instantly by double-click.

[xgfone]

Solved by #27521