remove broken/unsupported rapids_cpm_find usages in favor of rapids_find_package

[cwharris]

By using rapids_cpm_find we're implicitly stating that we support download and building packages. Excluding the CPM arguments from the call doesn't make it any better, since the error message produced by rapids_cpm_find when it does not find the package installed indicates that the CPM arguments should be added. In short, rapids_cpm_find doesn't do us any favors if we don't support downloading and building the package from source. Instead it just acts as a confusing wrapper around find_package. This PR replaces rapids_cpm_find with rapids_find_package and removes the broken build code for cudf, ucx, and boost.

If/when we decide to support building these packages from source, we can revisit rapids_cpm_find, but for now we require installing the packages ahead of time (this hasn't changed).

[drobison00]

Looks fine to me, assuming all the tests pass, and that it works fails with an appropriate message when we have to pull and build UCX.

@mdemoret-nv Do you remember why this was originally such a manual process?

[cwharris]

@drobison00 the error produced by find_package is very informative for anyone who's used to cmake and understands where/how packages should be installed (conda).

CMake Error at external/utilities/cmake/morpheus_utils/package_config/ucx/Configure_ucx.cmake:25 (find_package):
  By not providing "Finducx.cmake" in CMAKE_MODULE_PATH this project has
  asked CMake to find a package configuration file provided by "ucx", but
  CMake did not find one.

  Could not find a package configuration file provided by "ucx" (requested
  version 1.13) with any of the following names:

    ucxConfig.cmake
    ucx-config.cmake

  Add the installation prefix of "ucx" to CMAKE_PREFIX_PATH or set "ucx_DIR"
  to a directory containing one of the above files.  If "ucx" provides a
  separate development package or SDK, be sure it has been installed.
Call Stack (most recent call first):
  cmake/dependencies.cmake:39 (morpheus_utils_configure_ucx)
  CMakeLists.txt:135 (include)

[cwharris]

Still need to test this with Morpheus now that the utilities changes have been merged there.

[cwharris]

I've kept the old code as a comment, per @mdemoret-nv 's request, and used rapids_find_package instead of find_package so we have proper export sets.

[cwharris]

tested with Morpheus and it works. Need to update one line in MRC to get this working, since I renamed the boost configuration function.

[cwharris]

@drobison00 I don't have permissions to change labels, but because of the boost configuration function rename this is a breaking change now.

[cwharris]

/merge

[drobison00]

/merge