cmake: use COPYONLY rather than COPY_ONLY

Change-Id: I0e9a53fa64a91c90b4b0c60f96b873dd9acd76e2
vtkWrap: some uses of COPY_ONLY weren't even wrong

These instances are @ONLY, not meant to be COPYONLY which is what
COPY_ONLY might have indicated.

Change-Id: Iff456796cdd780fa9171713a0b286c9dc7036fe3
Merge topic 'fix-COPYONLY-usage' into master

d7f71542 vtkWrap: some uses of COPY_ONLY weren't even wrong
3bf2fb76 cmake: use COPYONLY rather than COPY_ONLY