paraview: don't use @rpath/ in the build tree either
This doesn't work because when CMake goes to rewrite library references
upon installation, it detects common prefixes and rewrites them all.
However, with plugins having their modules beside them and main
libraries being elsewhere, all @rpath/ prefixes get rewritten to the
same install name directory even though there could be different
LC_RPATH entries affecting each entry. To fix this until we move to
@loader_path and @executable_path everywhere, instead just avoid @rpath
completely for ParaView's build.
Needs paraview!3235 (merged) to actually work, but this is actually independent.