Search for libsodium and link ZMQLib to it

The LCG libzeromq is linked to libsodium, but pkg-config doesn't seem to propagate this, so explicitly search for and link to it. libsodium seems to be installed as a system library in all test systems, so this was not observed before.

added Build label

changed the description

/ci-test --merge

mentioned in merge request Allen!770 (merged)

added ci-test-triggered label

added RTA label

• [2022-02-14 10:33] Validation started with lhcb-master-mr#3699

mentioned in merge request !3426 (merged)

assigned to @thboettc

added cleanup label

resolved all threads

merged

mentioned in commit 65e70724

mentioned in issue Moore#390 (closed)