What typeface is used by macOS to render unicode glyphs?
All glyphs are Unicode glyphs! 

In the absence of fonts specified in the webpage itself, Safari will use its default font, Time New Roman. However, TNR does not have glyphs in the range shown on this page  so Safari cascades to its default for each Unicode range. 

For the glyphs in your screenshot, the pointing hand symbols, that seems to come from:

/System/Library/Fonts/Apple Symbols.ttf


Other glyphs on that page are from: 

/System/Library/Fonts/Apple Color Emoji.ttc. 

You can of course create outlined SVGs from any font character using a vector artwork editor like Adobe Illustrator, Affinity Designer, Graphic, or Inkscape.