grouper types should have tooltips that describe the type

the tooltip should be the same technology as a group result which has a tooltip of its description.

the text should be copied from excerpts like this:  (leave out the first sentence)

stemServiceRefFolderDescription = The ref folder contains reference groups. A reference group is a set of entities that is largely intended to be used by reference within access policy. Reference groups can be thought of as labels or tags that identify institutionally meaningful cohorts. Access policies often require cohorts organized via institutional affiliation (faculty, staff, student), a particular office or department (president's office, finance division, chaplain), program (chemistry students), and even residence or class year.

Tooltip should be used:

1. When displayed at top of folder/group
2. In the view-types screen
3. When we decide how to show type stuff in search results, then maybe there too