[input-] handle resizes during input or cell edit

[midichef]

In the middle of edit-cell or exec-longname, if you resize the terminal pushing the current cell offscreen, you get a curses error:

    File "/home/midichef/.venv/lib/python3.12/site-packages/visidata/_input.py", line 396, in editText
        v = widget.editline(vd.activeSheet._scr, y, x, w, attr=attr, updater=updater, bindings=bindings, clear=clear)
...
    File "/home/midichef/.venv/lib/python3.12/site-packages/visidata/_input.py", line 581, in _drawPrompt
        clipdraw(sheet._scr, y, 0, prompt, attr, w=sheet.windowWidth-rstatuslen-1)
...
    File "/home/midichef/.venv/lib/python3.12/site-packages/visidata/cliptext.py", line 242, in clipdraw_chunks
        scr.addstr(y, x, disp_column_fill*actualw, cattr.attr)  # clear whole area before displaying
    _curses.error: addwstr() returned ERR

This PR catches the error gracefully.

It was hard to connect this error to the resize event, because the stack trace would go to the terminal, and only be noticed much later on exiting visidata.

[midichef]

The test here did not really fail, it's the timeout trying to fetch http://visidata.org/usage.tsv that keeps happening, this time it had this error:
cannot open URL: [SSL: UNEXPECTED_EOF_WHILE_READING] EOF occurred in violation of protocol (_ssl.c:1010)

[midichef]

For testing, the most consistent way I have found to trigger the curses error (for gnome-terminal on Ubuntu) is: press Space to run exec-longname and then increase the font size with Ctrl+Shift+= aka Ctrl +