Summary

• Instead of rolling our own CPP-safe escaping routine, just use CMake’s built-in functionality for this. This makes our code a bit tidier, and the CMake provided implementation covers a number of cases that our in-house implementation did not.
• Use the CMakePushCheckState module to better isolate the state used during individual checks from each other. THis should help avoid obscure bugs resulting from state being leaked between checks.

Both of these are bringing things more in-line with best practices for CMake code.

Test Plan

CI still passes on this PR without issue.