Add icon pattern for Authors screen

[jspaaks]

blocked by decision in #455

We may need to introduce "question" texts over each text box, if we decide that that's where we will add the information icon.

[jspaaks]

After discussing this issue in #477, we have arrived at the following regarding ScreenAuthors / AuthorCardEditing:

• add vertical space between the rows of input fields
• add texts above each input field with a short description of what is expected of the user
• include a SchemaGuideLink icon with each text
• add an onhover hint to the SchemaGuideLink icon with text: Click to access specific documentation

The result should look more or less like:

and

[abelsiqueira]

Done in #483 and #484