gpui: Add cursor style methods of nesw nwse resize (#21801)

Release Notes:

- N/A

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This change adds two new methods to the cursor_style_methods function in
the gpui_macros crate (according to the Tailwind CSS documentation
https://tailwindcss.com/docs/cursor):
1. `cursor_nesw_resize`: Sets the cursor style to nesw-resize when
hovering over an element. This is useful for indicating resizing
diagonally from top-right to bottom-left.
2. `cursor_nwse_resize`: Sets the cursor style to nwse-resize when
hovering over an element. This is used for resizing diagonally from
top-left to bottom-right.