Convert remaining comment tests to the testing profile

Couple points that may require explanation:

+++ b/core/modules/comment/lib/Drupal/comment/Tests/CommentTestBase.phpundefined
@@ -69,7 +69,6 @@ function setUp() {
       'edit own comments',
       'post comments',
       'skip comment approval',
-      'access comments',
       'access content',

The diff here is misleading. I'd accidentally listed the permission twice in the previous patch, so this just removes the duplicate.

+++ b/core/modules/comment/lib/Drupal/comment/Tests/CommentNewIndicatorTest.phpundefined
@@ -41,8 +32,6 @@ public function testCommentNewCommentsIndicator() {
-    $count = $this->xpath('//div[@id=:id]/div[@class=:class]/ul/li', array(':id' => 'node-' . $this->node->nid, ':class' => 'link-wrapper'));
-    $this->assertTrue(count($count) == 1, 'One child found');

@@ -75,8 +64,6 @@ public function testCommentNewCommentsIndicator() {
-    $count = $this->xpath('//div[@id=:id]/div[@class=:class]/ul/li', array(':id' => 'node-' . $this->node->nid, ':class' => 'link-wrapper'));
-    $this->assertTrue(count($count) == 2, print_r($count, TRUE));

These assertions were completely superfluous and assumed specific markup and a very specific environment configuration completely unrelated to whether and when the "new comments" link and marker are rendered. So, I removed them.