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/LADTable/components/LadTableSet.vue

@@ -51,10 +51,6 @@
 </table>
 </template>
 
-<style lang="scss">
-
-</style>
-
 <script>
 import LadRow from './LADRow.vue';