Improve viewer creator styling (#2743)

* tooltip and remove divider for viewer-creator

* rely on index instead of name

* no divider on far left or between import button and next item
* achieve padding on right side of import button instead of assuming next entry

jdaviz/app.vue

@@ -36,13 +36,14 @@
       </div>
     </v-overlay>
     <v-app-bar color="toolbar" dark :dense="state.settings.dense_toolbar" flat app absolute clipped-right :style="checkNotebookContext() ? 'margin-left: 1px; margin-right: 1px' : ''">
-      <v-toolbar-items v-for="item in state.tool_items">
-        <v-divider v-if="['g-data-tools', 'g-subset-tools'].indexOf(item.name) === -1" vertical style="margin: 0px 10px"></v-divider>
-        <v-divider v-else-if="item.name === 'g-subset-tools'" vertical style="margin: 0px 10px; border-width: 0"></v-divider>
+      <v-toolbar-items v-for="(item, index) in state.tool_items">
+        <!-- this logic assumes the first entry is g-data-tools, if that changes, this may need to be modified -->
+        <v-divider v-if="index > 1" vertical style="margin: 0px 10px"></v-divider>
         <j-tooltip v-if="['cubeviz', 'mosviz'].indexOf(config) !== -1 && item.name == 'g-data-tools' && state.data_items.length !== 0"></j-tooltip>
         <j-tooltip v-else :tipid="item.name">
           <jupyter-widget :widget="item.widget" :key="item.name"></jupyter-widget>
         </j-tooltip>
+        <v-divider v-if="item.name === 'g-data-tools'" vertical style="margin: 0px 10px; border-width: 0"></v-divider>
       </v-toolbar-items>
       <v-spacer></v-spacer>
       <v-toolbar-items>

jdaviz/components/tooltip.vue

@@ -40,6 +40,8 @@ const tooltips = {
 
   'g-data-tools': 
     'Load data from file',
+  'g-viewer-creator':
+     'Create a new viewer',
   'g-subset-tools': 
     'Select, create, and delete subsets',
   'g-subset-mode':