Refine status bar design (#34324)

Experimenting with a set of standardized icons and polishing spacing a
little bit.

Release Notes:

- N/A

crates/icons/src/icons.rs

@@ -247,6 +247,7 @@ pub enum IconName {
     SwatchBook,
     Tab,
     Terminal,
+    TerminalAlt,
     TextSnippet,
     ThumbsDown,
     ThumbsUp,