Make install breaks the library links in the plugins

[balazsdukai]

This is an issue with all of the plugins and not with geoflow itself, so I didn't know where else to put it.

Doing a cmake --build . --target install breaks the links to the libraries of a plugin (but not for geoflow).
Doing a simple cp of the compiled plugin to the plugins directory preserves the links.

Interestingly, running cmake and build and install in the root of the geoflow-bundle repo installs the plugins with the correct links.