[Feature Request] EvEditor - Do not add string-casted None literals to buffer

[strikaco]

Is your feature request related to a problem? Please describe.

When editing an attribute using set/edit, if the attribute in question is unset or otherwise None, the string "None" is prepended to the buffer.

----------Line Editor [object/name]-----------------------------------------
01| None
----------[l:01 w:001 c:0004]------------(:h for help)------------------------

Using the editor to set an initial value requires the first step to be :x 1 in order to actually start with a clean slate.

Describe the solution you'd like

I'd suggest that if the existing attribute value is anything other than a string, the editor should at least warn the user about the type mismatch.

In cases where the value is the literal None or otherwise evaluates to False, these should simply not be appended to the buffer.

[strikaco]

I do see some existing commands that implement the editor perform typechecking, but this could be better enforced by the editor itself.

if old_value is not None and not isinstance(old_value, str):
            typ = type(old_value).__name__
            self.caller.msg(
                "|RWARNING! Saving this buffer will overwrite the "
                "current attribute (of type %s) with a string!|n" % typ
            )
            return str(old_value)

[Griatch]

The editor already defaults to warning in red if trying to edit a non-string. I made a previously undefined Attribute come out as an empty string in set/edit command also added a confirmation question to confirm, since that use of the editor is so likely to encounter non-strings. Closing.