bug#45199: 28.0.50; [PATCH] Make goto-char offer the number at point as default

[Juri Linkov]

>> Here's a patch where it uses number-at-point:
>
> Looks good to me.
>
>> Also this patch adds the same useful property from goto-line to goto-char.
>> When there is no number at point, then M-n gets the current char position
>> number for editing, so the user can decrease or increase it
>> relative to the current position:
>
> Yeah, that sounds useful.

Now pushed to master.