Bug#915241: Salsa MR: Merge from experimental branch and Enhance description

[Nicholas D Steeves]

Package: src:heaptrack
Severity: normal

https://salsa.debian.org/science-team/heaptrack/merge_requests/1

This MR merges Anton's work from experimental and enhances the
description to make heaptrack discoverable via keyword search, plus
adds a couple of extremely brief comparisons with Valgrind.

When I was debugging a dbus+kde memory ballooning/memleak issue, I was
not able to find heaptrack with a keyword search, so packaged
memleax. Having now discovered heaptrack via the memleax bugtracker
(yes, really!) I believe the best path forward is to make heaptrack
discoverable and scrap my work on memleax.

Thank you for considering this MR,
Nicholas