Fix a couple of layout issues caused by tooltip and gr-button migrations

When gr-button was migrated to Lit it was missed that @apply does not
work in static styles, so those styles should have been put into the
render() method, which is a workaround that is already in place in
various other Lit elements. But we want to get rid of css mixins anyway.
So I took the opportunity in this change to get rid of the --gr-button
mixin altogether, because it was clear that I would have to make a
careful pass over the entire UI anyway with pixel by pixel comparison.

So this ended up also fixing a couple of unrelated issues that were
recently broken. I have basically just opened gerrit-review and compared
against the Dev Helper version, and worked my way through most of the
important pages and widgets until I reached nearly pixel perfect
identity.

gr-button being inline-block inside gr-tooltip-content is a bit
unfortunate. gr-button would probably be easier to deal with, if it had
display:block, but that is a change for another day.

Change-Id: I7d3e57a43148000053ef63232dcb1945c1ad40be
diff --git a/polygerrit-ui/app/elements/checks/gr-checks-results.ts b/polygerrit-ui/app/elements/checks/gr-checks-results.ts
index 68c7957..245660d 100644
--- a/polygerrit-ui/app/elements/checks/gr-checks-results.ts
+++ b/polygerrit-ui/app/elements/checks/gr-checks-results.ts
@@ -816,6 +816,7 @@
         }
         .headerTopRow .right .goToLatest gr-button {
           margin-right: var(--spacing-m);
+          --gr-button-padding: var(--spacing-s) var(--spacing-m);
         }
         .headerBottomRow iron-icon {
           color: var(--link-color);
@@ -975,23 +976,11 @@
   }
 
   override render() {
-    // To pass CSS mixins for @apply to Polymer components, they need to appear
-    // in <style> inside the template.
-    /* eslint-disable lit/prefer-static-styles */
-    const style = html`<style>
-      .headerTopRow .right .goToLatest gr-button {
-        --gr-button: {
-          padding: var(--spacing-s) var(--spacing-m);
-          text-transform: none;
-        }
-      }
-    </style>`;
     const headerClasses = classMap({
       header: true,
       notLatest: !!this.checksPatchsetNumber,
     });
-    return html`${style}
-      <div class="${headerClasses}">
+    return html` <div class="${headerClasses}">
         <div class="headerTopRow">
           <div class="left">
             <h2 class="heading-2">Results</h2>