Use FullscreenButton in SnippetNote

[vienai8d]

Current behavior

Snippet note and Markdown note have fullscreen buttons, but those tooltip texts are different as follows.

Tooltip text of Markdown Note

Tooltip text of Sinppet Note

• The tooltip text of Markdown Note is Fullscreen(Command(⌘)+B).
• Snippet note's tooltip text is Fullscreen.

Expected behavior

I expect Snippet note uses FullscreenButton instead of current button. Therefore, the Snippet note's tooltip text will be Fullscreen(Command(⌘)+B)).