Update UI of tool messages

- Bring tool messages in line with original envisioned UI of: https://screenshot.googleplex.com/9yZCX636LzpMrgc
  - In particular this represents more descriptive names. FWIW we already had this tech we just weren't passing around information correctly (`displayName` vs. `name`)
 - Add gray to our list of color pallete's and removed Background (unused)
 - Re-enabled representing canceled messages
 - Migrated back towards a cleaner tool message design of status symbols & border colors vs. overly verbose text.
 - Removed border from confirmation diffs.
Fixes https://b.corp.google.com/issues/412598909

packages/cli/src/ui/components/messages/ToolGroupMessage.tsx

@@ -22,11 +22,18 @@ export const ToolGroupMessage: React.FC<ToolGroupMessageProps> = ({
   toolCalls,
   onSubmit,
 }) => {
-  const hasPending = toolCalls.some((t) => t.status === ToolCallStatus.Pending);
-  const borderColor = hasPending ? Colors.AccentYellow : Colors.AccentBlue;
+  const hasPending = !toolCalls.every(
+    (t) => t.status === ToolCallStatus.Success,
+  );
+  const borderColor = hasPending ? Colors.AccentYellow : Colors.AccentCyan;
 
   return (
-    <Box flexDirection="column" borderStyle="round" borderColor={borderColor}>
+    <Box
+      flexDirection="column"
+      borderStyle="round"
+      borderDimColor={hasPending}
+      borderColor={borderColor}
+    >
       {toolCalls.map((tool) => (
         <React.Fragment key={tool.callId}>
           <ToolMessage