MacVim defaults clean up and modernization

Just a general issue for improving the defaults for what I consider to be what constitutes a modern GUI text editor. Changing defaults is always contentious, and therefore should require a bit of thoughts behind them. None of the proposed defaults below change any features and they would just require either a vimrc change or changing them in the user settings. Just listing them below to keep track of and to gather feedbacks:

• set macligatures
• MMShareFindPboard should be NO.
• Overlay scroll bar (once implemented)
• set guifont=-monospace-

Implemented:

• #1528
  • Smooth resizing defaults to on (feature originally implemented in #1276)
  • set guioption+=k

Update: I have made a comment for each of the new option in case people want to vote on them using emoji reactions. (Per suggested by a comment)

Esamina i valori predefiniti proposti in questa issue, inclusi macligatures, MMShareFindPboard, le barre di scorrimento sovrapposte e guifont, insieme alle modifiche già implementate in #1528. Controlla prima la discussione collegata e i feedback con emoji; il lavoro sarà completo solo quando il progetto avrà preso una decisione su quali valori predefiniti modificare e dove collocare ciascuna modifica.