Overhaul interaction icons
The current interaction buttons are too close together, have inconsistent margins (with or without post stats enabled) and need a little bit of love. The icon line widths were also inconsistent, because we are mixing some Breeze icons (the bookmark and menu overflow) in with our own. This MR aims to solve that by fixing the SVGs and also fixing the margins, by making the spacing better for full-width users. For small-width screens and mobile devices, the spacing between buttons are now evenly spaced which makes more sense.
Also included is an edited version of the Breeze bookmarks icon (so now all of the icons can be filled when interacted with!) and the code is much cleaner and easier to read.