Search UI complete (#3)

"Back" doesn't preserve search results; need to fix that before this is done

src/JobsJobsJobs/Client/Shared/Collapsible.razor

@@ -0,0 +1,25 @@
+<div class="card">
+  <div class="card-header">
+    <a href="#" class="@(Collapsed ? "jjj-c-collapsed" : "jjj-c-open")"
+       @onclick=@Toggle @onclick:preventDefault>
+      @HeaderText
+    </a>
+  </div>
+  @if (!Collapsed)
+  {
+    <div class="card-body">@ChildContent</div>
+  }
+</div>
+
+@code {
+    [Parameter]
+    public RenderFragment ChildContent { get; set; } = default!;
+
+    [Parameter]
+    public bool Collapsed { get; set; } = false;
+
+    [Parameter]
+    public string HeaderText { get; set; } = "Toggle";
+
+    private void Toggle() => Collapsed = !Collapsed;
+}

src/JobsJobsJobs/Client/Shared/Collapsible.razor.css

@@ -0,0 +1,16 @@
+a.jjj-c-collapsed,
+a.jjj-c-open {
+  text-decoration: none;
+  font-weight: bold;
+  color: black;
+}
+a.jjj-c-collapsed:hover,
+a.jjj-c-open:hover {
+  cursor: pointer;
+}
+.jjj-c-collapsed::before {
+  content: '\2b9e \00a0';
+}
+.jjj-c-open::before {
+  content: '\2b9f \00a0';
+}