allow installing R packages in a different place than currently installed R packages #8988
Description
currently if we set EASYBUILD_INSTALLPATH to a different location from where already installed R packages are, EB will only check in the EASYBUILD_INSTALLPATH for existing packages.
it would be nice if we could tell EB to look for R packages in a given path but install in another path.
this could be useful when generating test reports for PRs, especially when additional R packages are added to an already existing easyconfig.