fix: separate out merge-install and install-base

Author: darrenjkt

generate_parameter_library_py/generate_parameter_library_py/setup_helper.py

@@ -33,7 +33,7 @@
 
 
 def generate_parameter_module(
-    module_name, yaml_file, validation_module='', merge_install_base=None
+    module_name, yaml_file, validation_module='', install_base=None, merge_install=False
 ):
     # TODO there must be a better way to do this. I need to find the build directory so I can place the python
     # module there
@@ -54,10 +54,11 @@ def generate_parameter_module(
             tmp = tmp.split('.')
             py_version = f'python{tmp[0]}.{tmp[1]}'
 
+            if not install_base:
+                install_base = os.path.join(colcon_ws, 'install')
+
             install_base = (
-                merge_install_base
-                if merge_install_base
-                else os.path.join(colcon_ws, 'install', pkg_name)
+                install_base if merge_install else os.path.join(install_base, pkg_name)
             )
             install_dir = os.path.join(
                 install_base,