[REQ] some way of making multiple copies in the corpus more obvious

[kchall]

Is your feature request related to a problem? If so, please describe.
I keep forgetting / not noticing when there are multiple glosses linked to a single entry in a corpus, and getting confused about why there are so many entries / how one entry is connected to another if one is edited.

Describe the solution / new feature you'd like
Possibly two things or variants on these:

1. Similar to the summary window, highlighting one entry could lightly highlight all the glosses it's associated with, so that you don't have to rely on noticing identical entry ID numbers. (See mock-up image below.)

2. And/or have an option to display only unique entries in the corpus, maybe with the first gloss shown by default. (See mock-up image below.)