Problem: Memory is leaked in tabline click definitions since
https://github.com/neovim/neovim/pull/21008.
Solution: Add back a call to `stl_clear_click_defs()` that was lost in
the refactor PR.
With #20374 tabline option is marked with 'statuslines' redraw flag.
But 'statuslines' doesn't redraw tabline. As a result, tabline doesn't
get redrawn when tabline option is set and statuslines get unnecessarily redrawn.
This patch fixes the issue by adding a new redraw flag P_RTABL to redraw
tabline.
* Add buffer information to tabline_update
Most terminal implementations of the tabline display buffer and tab
information. Many neovim-qt users disable GuiTabline because it lacks
functionality provided in the terminal implementation.
The tabline_update event should include buffer information too, so client GUIs
can display rich useful tabs.
It is perfectly fine and expected to detach from the screen just by
the UI disconnecting from nvim or exiting nvim. Just keep detach() in
screen_basic_spec, to get some coverage of the detach method itself.
This avoids hang on failure in many situations (though one could argue
that detach() should be "fast", or at least "as fast as resize",
which works in press-return already).
Never use detach() just to change the size of the screen, try_resize()
method exists for that specifically.
