Redesign template parameter pages to be more space efficient

* Show label, input and remove control on a single line
* Right align label to conserve vertical space without sacrificing
  fill-out speed
* Show description in gray text below the input
* Show remove button only when page is active
* Make description lighter when page is innactive

Change-Id: Iaa09f3bf909ccd415de7af8f428495fef3046893