(tty_text_width): Use <const Charc *> instead of <const Emchar *>; use

(tty_text_width): Use <const Charc *> instead of <const Emchar *>; use
`charc_string_displayed_columns' instead of
`emchar_string_displayed_columns'.
(tty_output_display_block): Use <Charc_dynarr *> instead of
<Emchar_dynarr *> for buf; modify for <structure rune> change; use
`tty_output_charc_dynarr' instead of `tty_output_emchar_dynarr'.
(tty_output_charc_dynarr_dynarr): New variable; renamed from
`tty_output_emchar_dynarr_dynarr'.
(tty_output_charc_dynarr): New function; delete
`tty_output_charc_dynarr'.