update search colors by theme, change style for unselected match

packages/codemirror/style/index.css

@@ -108,7 +108,15 @@ pre.CodeMirror-line {
 }
 
 .CodeMirror-selectedtext.cm-searching {
-  background-color: orangered !important;
+  background-color: var(--jp-search-selected-match-background-color) !important;
+  color: var(--jp-search-selected-match-color) !important;
+}
+
+.cm-searching {
+  background-color: var(
+    --jp-search-unselected-match-background-color
+  ) !important;
+  color: var(--jp-search-unselected-match-color) !important;
 }
 
 .CodeMirror-focused .CodeMirror-selected {

packages/theme-dark-extension/style/variables.css

@@ -374,4 +374,10 @@ all of MD as it is not optimized for dense, information rich UIs.
   --jp-search-toggle-off-opacity: 0.5;
   --jp-search-toggle-hover-opacity: 0.75;
   --jp-search-toggle-on-opacity: 1;
+  --jp-search-selected-match-background-color: rgb(255, 225, 0);
+  --jp-search-selected-match-color: black;
+  --jp-search-unselected-match-background-color: var(
+    --jp-inverse-layout-color0
+  );
+  --jp-search-unselected-match-color: var(--jp-ui-inverse-font-color0);
 }

packages/theme-light-extension/style/variables.css

@@ -371,4 +371,10 @@ all of MD as it is not optimized for dense, information rich UIs.
   --jp-search-toggle-off-opacity: 0.4;
   --jp-search-toggle-hover-opacity: 0.65;
   --jp-search-toggle-on-opacity: 1;
+  --jp-search-selected-match-background-color: rgb(255, 245, 0);
+  --jp-search-selected-match-color: black;
+  --jp-search-unselected-match-background-color: var(
+    --jp-inverse-layout-color0
+  );
+  --jp-search-unselected-match-color: var(--jp-ui-inverse-font-color0);
 }