Dynamically set screen based on current terminal size

[shamrice]

Use "CBL_GET_SCR_SIZE" to get the current terminal size and then set up screen accordingly. This does not need to be "on the fly" and can be done either between screens or via configuration at start up.

Example usage:

In working/local-storage section

       01  ws-scr-lines         usage binary-char unsigned.
       01  ws-scr-cols          usage binary-char unsigned.
       
       01  ws-scr-lines-disp    pic 99.
       01  ws-scr-cols-disp     pic 99.

In procedure division:

           call "CBL_GET_SCR_SIZE" using ws-scr-lines, ws-scr-cols          
           
           move ws-scr-lines to ws-scr-lines-disp
           move ws-scr-cols to ws-scr-cols-disp