more dialog:function() possibilities

[Omar-Abdul-Azeez]

Currently these are the only things possible with the current modify function

that's a little lackluster. A couple more things we can modify are

1. onclick, onchange, onrelease functions
2. options for combobox

and two more functions I feel are needed

1. dialog:delete() which should delete the element with the specified id
2. dialog:replace() should delete the element with the given id and create a new element with a new id in the same place

[Omar-Abdul-Azeez]

ok... I swear I was testing it with option and it didn't work so I assumed only the parameters specified in the documentation are supported. I was looking at dialog_class.cpp to see if it's simple enough to do myself and found that most of these are supported with a comment for support of options in the future. so I tested it again and it worked(???) whatever it is that was happening idk

anyways since most of this is already supported I'll edit it out. one last thing... if this should be in the Aseprite repo and not here feel free to close and move the issue or let me know and I will :)