Fixes for #4623 (#4624)

- New `c-object-view` class;
- Removed CSS class special-casing in ObjectView.vue;
- Removed unused `l-shell__main-object-view` class;
- Fixed CSS selector for Condition Widget display in main view;

Co-authored-by: John Hill <john.c.hill@nasa.gov>
Co-authored-by: Shefali Joshi <simplyrender@gmail.com>

src/plugins/conditionWidget/components/condition-widget.scss

@@ -56,7 +56,7 @@ a.c-condition-widget {
 }
 
 // When the widget is in the main view, center it in the space
-.l-shell__main-container > .c-condition-widget {
+.l-shell__main-container > * > .c-condition-widget {
     position: absolute;
     top: 50%;
     left: 50%;