fix(colors): override element styling and tweak colors for card and item

[brandyscarney]

• Refactor card to add color/mode classes to header, title, content
• Generate colors for the card itself, the header, the content, and the
  title using the color input
• Adds e2e test for card colors
• Refactor item to override paragraph color in item w/ color, update activated colors
• Adds e2e test for item colors

Closes #9081 Closes #8330

Snapshot for these changes: http://ionic-snapshot-go.appspot.com/ionic2/snapshots/s2n/tdu/chrome_400x800#db69ffb2

What this PR does NOT do:

• It does not style buttons in items or cards with the color input, we can discuss this but it would end up getting messy real quick if we change the default button colors in cards/items with a color. Therefore if a user makes an item primary they will need to give the button a color because it will default to primary.