Certificate management alert icons implementation and alignment

- Replaces background image icons with icon directive
- Sizes and aligns icons in certificate table

TODO:
- Remove critical icon background image in separate commit

Signed-off-by: Dixsie Wolmers <dixsiew@gmail.com>
Change-Id: I2e10bc3f3432331b6dd9354dbcd0e32480894ece
diff --git a/app/configuration/styles/certificate.scss b/app/configuration/styles/certificate.scss
index 0eaa7c0..a7c57f2 100644
--- a/app/configuration/styles/certificate.scss
+++ b/app/configuration/styles/certificate.scss
@@ -80,6 +80,12 @@
     }
     display: none;
   }
+  .certificate__status-icon {
+    width: 1.2em;
+    svg {
+      margin-bottom: .2em;
+    }
+  }
   .certificate__buttons-cell {
     @include mediaQuery(small) {
       width: 10%;