patch 9.1.1562: close button always visible in the 'tabline'

patch 9.1.1562: close button always visible in the 'tabline'

Problem:  close button "X" is visible in the non-GUI 'tabline', even
          when the mouse is disabled
Solution: only show the button when 'mouse' contains any of the flags
          "anvi" (Girish Palya)

The tabline always displays an "X" (close) button, and the info popup
shows both a close button and a resize handle—even when the mouse is
disabled. These UI elements are only actionable with the mouse and serve
no purpose for keyboard users who disable the mouse. Displaying
non-functional, clickable elements in a non-GUI environment is
misleading and adds unnecessary visual clutter.

So remove the close button and resize handle when the mouse is disabled.
They appear again when mouse is enabled.

closes: #17765

Signed-off-by: Girish Palya <girishji@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>