The left panel of the explore view has become crowded and overwhelming
overtime. This PR adds functionality to collapse the control sections,
and sets most sections to be collapse by default as the explore view
opens up.
* breakdown `Query` section for most viz
* bring filters to the top, under Query section
* collapse most sections by default
* removed confusing outdated description for Filter section
* Allow for multiple color schemes
1. create ColorSchemeControl component
2. using the same new control component for linear colors
* add color spectum for linear color scheme
* remove dup css
* fix controls setting for linear color scheme
* minor fix by code review comment
