Better management of jemalloc presence/absence

[fab-10]

Signed-off-by: Fabio Di Fabio [email protected]

PR description

If jemalloc is not present, an error message is printed, but the absence of jemalloc is not a real error, so in this PR we try to understand if jemalloc is available and print messages that are easier for the user to understand, and invite him to install jemalloc to get better memory usage

Fixed Issue(s)

Documentation

• [x] I thought about documentation and added the doc-change-required label to this PR if updates are required.

Changelog

• [x] I thought about the changelog and included a changelog update if required.