Style Timestrip and Plan views (#3715)

* Time Strip styling WIP

- Plan activity rects now don't use corner radius if smaller than the
radius, and use a minimum width of 1;
- Visual refinements to time axis and swimlanes;
- Refactored CSS-related class names and file `swim-lane` to `swimlane`;

* Compute row span dynamically

* Remove activities only in the current plan when refreshing

* Time Strip styling WIP

- Refinement and consolidation of CSS between c-plan and c-timeline;
- CSS cleanups;

* Time Strip styling WIP

- Added calculated activity text coloring based on background fill
color;

* Fix timestrip time bounds syncing

* Unlisten for bounds

* Update name of css file

* Adds test for time system axis in timestrip

Co-authored-by: Joshi <simplyrender@gmail.com>

src/styles/vue-styles.scss

@@ -34,7 +34,7 @@
 @import "../ui/components/object-label.scss";
 @import "../ui/components/progress-bar.scss";
 @import "../ui/components/search.scss";
-@import "../ui/components/swim-lane/swim-lane.scss";
+@import "../ui/components/swim-lane/swimlane.scss";
 @import "../ui/components/toggle-switch.scss";
 @import "../ui/components/timesystem-axis.scss";
 @import "../ui/inspector/elements.scss";