Theming (#2567)

* Separate Vue component styles out from SFCs.
* Added 'MCT.prototype.getAssetPath' and using 'openmct.setAssetPath' to get relative path for assets.
* Re-implements `openmct.plugins.Snow()`, and `openmct.plugins.Espresso()` (as well as a new theme `openmct.plugins.Maelstron()`)

src/plugins/displayLayout/components/EditMarquee.vue

@@ -45,66 +45,6 @@
 </div>
 </template>
 
-<style lang="scss">
-    @import "~styles/sass-base";
-
-    .c-frame-edit {
-        // In Layouts, this is the editing rect and handles
-        display: none; // Set to display: block in DisplayLayout.vue
-        pointer-events: none;
-        @include abs();
-        border: $editMarqueeBorder;
-
-        &__handle {
-            $d: 6px;
-            $o: floor($d * -0.5);
-            background: $editFrameColorHandleFg;
-            box-shadow: $editFrameColorHandleBg 0 0 0 2px;
-            pointer-events: all;
-            position: absolute;
-            width: $d; height: $d;
-            top: auto; right: auto; bottom: auto; left: auto;
-
-            &:before {
-                // Extended hit area
-                @include abs(-10px);
-                content: '';
-                display: block;
-                z-index: 0;
-            }
-
-            &:hover {
-                background: $editUIColor;
-            }
-
-            &--nwse {
-                cursor: nwse-resize;
-            }
-
-            &--nw {
-                cursor: nw-resize;
-                left: $o; top: $o;
-            }
-
-            &--ne {
-                cursor: ne-resize;
-                right: $o; top: $o;
-            }
-
-            &--se {
-                cursor: se-resize;
-                right: $o; bottom: $o;
-            }
-
-            &--sw {
-                cursor: sw-resize;
-                left: $o; bottom: $o;
-            }
-        }
-    }
-</style>
-
-
 <script>
 import LayoutDrag from './../LayoutDrag'