Select component style tweaks (#8725)

* match width to trigger

* tweak selected style

frontend/src/metabase/components/ColumnarSelector.css

@@ -55,10 +55,8 @@
 }
 
 .ColumnarSelector-row--selected {
-  color: inherit !important;
+  color: var(--color-brand);
   background: white;
-  border-top: var(--border-size) var(--border-style) var(--color-border);
-  border-bottom: var(--border-size) var(--border-style) var(--color-border);
 }
 
 .ColumnarSelector-row--disabled {

frontend/src/metabase/components/Select.jsx

@@ -57,7 +57,7 @@ class BrowserSelect extends Component {
   };
   static defaultProps = {
     className: "",
-    width: 320,
+    width: 300,
     height: 320,
     rowHeight: 40,
     multiple: false,