[Language Services] Modules completions don't behave as expected in all cases

[gcampbell-msft]

Brief Issue Summary

If I type FindPython at the beginning of a line and use the completion, it helps me out and creates the find_package call with the right arguments.

However, if I already have typed the find_package and am now putting find_package(FindPython and then accept the completion, it still creates the find_package command, resulting in

find_package(find_package(Python REQUIRED))

This is erroneous.