Update certificate management page consistency

This change applies global styles to improve
page layout consistency and modal management

- Adds page and section styles
- Removes unused styles
- Creates individual html files for modals
- Updates certificate modals to bootstrap modal
- Updates global styles for input file field in file-upload.scss

TODO:
- Update certificate table with table component in separate commit
- Update CSR modal to use global form-field styles in separate commit

Signed-off-by: Dixsie Wolmers <dixsiew@gmail.com>
Change-Id: I9b800cb684740da1a9168294433e726efb0f9d0e
diff --git a/app/common/styles/elements/file-upload.scss b/app/common/styles/elements/file-upload.scss
new file mode 100644
index 0000000..4704d6d
--- /dev/null
+++ b/app/common/styles/elements/file-upload.scss
@@ -0,0 +1,56 @@
+/**
+  * Used for file upload
+  * Markup
+      <div class="file-upload">
+        <label for="upload_cert_new" class="file-upload-btn btn btn-secondary" tabindex="0">Choose file</label>
+        <input
+          name="upload_cert_new"
+          id="upload_cert_new"
+          type="file"
+          file="newCertificate.file"
+          class="file-upload-input"/>
+        <div class="form__field file-upload-container">
+          <span ng-hide="newCertificate.file">No file selected</span>
+          <span>{{ newCertificate.file.name }}</span>
+          <button
+            type="reset"
+            class="btn file-upload-reset"
+            ng-if="newCertificate.file.name"
+            ng-click="newCertificate.file = '';"
+            aria-label="remove selected file">
+            <icon file="icon-close.svg" aria-hidden="true"></icon>
+          </button>
+        </div>
+      </div>
+*/
+
+// Choose/upload button
+.file-upload-input {
+  width: 1px;
+  height: 1px;
+  opacity: 0;
+  overflow: hidden;
+  position: absolute;
+  z-index: -1;
+}
+
+.file-upload-input:focus {
+  outline: 0.2rem solid $base-02--04;
+}
+
+// File name of uploaded file field
+.file-upload-container {
+  background: $background-02;
+  padding: 0.5rem;
+  span {
+    padding-left: .5rem;
+  }
+  .file-upload-reset {
+    float: right;
+    margin-top: -.5rem;
+    icon {
+      margin-right: -1.7em;
+      margin-left: -1.5em;
+    }
+  }
+}