fix(views): removes notices from views used in theme sandbox

This handles missing parameters in some input views; fixes the @uses
statement within the user picker view the the values; adds the missing
developers/ispum text in developers views; moves the ThemeSandboxObject
class to its own file; and adds a language string for missing view params.
Merge pull request #6665 from mrclay/notices

fix(views): removes notices from views used in theme sandbox