New & updated icons from sprint merge. (#651)

**What's new**
Beaker Add / 20, 24 / Filled & Regular
Beaker Dismiss / 20, 24 / Filled & Regular
Document Cube / 20, 24 / Filled & Regular
Drawer / 20, 24 / Filled & Regular
Filmstrip Image / 20, 24 / Filled & Regular
Number Circle 0 / 16, 20, 24, 28, 32, 48 / Filled & Regular
Number Circle 6 / 16, 20, 24, 28, 32, 48 / Filled & Regular
Number Circle 7 / 16, 20, 24, 28, 32, 48 / Filled & Regular
Number Circle 8 / 16, 20, 24, 28, 32, 48 / Filled & Regular
Number Circle 9 / 16, 20, 24, 28, 32, 48 / Filled & Regular
Server / 12 / Filled & Regular
Square Hint Hexagon / 12, 16, 20, 24, 28, 32, 48 / Filled & Regular
Tab Desktop Multiple Add / 16 / Filled & Regular
Tab Desktop Multiple / 16 / Filled & Regular
Target Add / 20, 24 / Filled & Regular
Target Dismiss / 20, 24 / Filled & Regular
Text Header 1 Lines Caret / 16, 20, 24 / Filled & Regular
Text Header 1 Lines / 16, 20, 24 / Filled & Regular
Text Header 2 Lines Caret / 16, 20, 24 / Filled & Regular
Text Header 2 Lines / 16, 20, 24 / Filled & Regular
Text Header 3 Lines Caret / 16, 20, 24 / Filled & Regular
Text Header 3 Lines / 16, 20, 24 / Filled & Regular

**What's updated**
Beaker / 20 / Filled & Regular
Desktop Speaker Off / 20, 24 / Filled & Regular
Desktop Speaker / 20, 24 / Filled & Regular
Edit Arrow Back / 16 / Filled & Regular
Edit Off / 16 / Filled & Regular
Edit Prohibited / 16 / Filled & Regular
Number Circle 1 / 16 / Filled & Regular
Number Circle 2 / 16 / Filled & Regular
Number Circle 3 / 16 / Filled & Regular
Number Circle 4 / 16 / Filled & Regular
Number Circle 5 / 16 / Filled & Regular
Square Hint Arrow Back / 16 / Filled
Square Hint / 16 / Filled