Move the logic inferring the value of CMAKE_INSTALL_PREFIX to it's …

…own function (#74)

* The `morpheus_utils_initialize_package_manager` needs to be called prior to calling `project`, however the `CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT` isn't defined until after `project` has been called.
* Moves `CMAKE_INSTALL_PREFIX` logic to a new function named `morpheus_utils_initialize_install_prefix`
* This change is needed for nv-morpheus/Morpheus#1776

Authors:
  - David Gardner (https://github.com/dagardner-nv)

Approvers:
  - Michael Demoret (https://github.com/mdemoret-nv)

URL: #74

cmake/morpheus_utils/environment_config/rapids_cmake/register_api.cmake

@@ -73,7 +73,11 @@ function(morpheus_utils_initialize_package_manager
 )
   # Ensure rapids CMake is setup
   include(${CMAKE_CURRENT_FUNCTION_LIST_DIR}/ensure_rapids_cmake_init.cmake)
+endfunction()
 
+function(morpheus_utils_initialize_install_prefix
+    USE_CONDA_VAR_NAME
+)
   set(USE_CONDA ${${USE_CONDA_VAR_NAME}})
 
   if(USE_CONDA AND DEFINED ENV{CONDA_PREFIX})