Revert function to get memory context stats for processes
Due to concerns raised about the approach, and memory leaks found
in sensitive contexts the functionality is reverted. This reverts
commits
45e7e8ca9,
f8c115a6c,
d2a1ed172,
55ef7abf8 and
042a66291
for v18 with an intent to revisit this patch for v19.
Discussion: https://postgr.es/m/594293.
1747708165@sss.pgh.pa.us