fix(podman): fix blocked thread on container inspection request

[andrewazores]

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---

Related to #1514

Description of the change:

Executes the Podman API request for listing containers on the Vert.x worker pool, and the subtask request for inspecting individual containers (if needed: no jmxHost label or jmxUrl label) on a worker thread.

Motivation for the change:

This fixes a bug where the executor thread gets blocked when it needs to list containers and then further inspect them. This blockage results in failure of the platform client to discover containers.

How to manually test:

1. Apply the patch below, then:
2. Run CRYOSTAT_IMAGE=quay.io... sh run.sh...

diff --git a/run.sh b/run.sh
index 9d322386..e58ca4f7 100755
--- a/run.sh
+++ b/run.sh
@@ -123,9 +123,7 @@ podman run \
     --name cryostat \
     --user 0 \
     --label io.cryostat.discovery="true" \
-    --label io.cryostat.jmxHost="localhost" \
-    --label io.cryostat.jmxPort="0" \
-    --label io.cryostat.jmxUrl="service:jmx:rmi:///jndi/rmi://localhost:0/jmxrmi" \
+    --label io.cryostat.jmxPort="${CRYOSTAT_RJMX_PORT}" \
     --memory 768M \
     --mount type=bind,source="$(dirname "$0")/archive",destination=/opt/cryostat.d/recordings.d,relabel=shared \
     --mount type=bind,source="$(dirname "$0")/certs",destination=/certs,relabel=shared \
@@ -136,7 +134,7 @@ podman run \
     --mount type=bind,source="$(dirname "$0")/probes",destination=/opt/cryostat.d/conf.d/probes.d,relabel=shared \
     -v "$XDG_RUNTIME_DIR"/podman/podman.sock:/run/user/0/podman/podman.sock:Z \
     --security-opt label=disable \
-    -e CRYOSTAT_ENABLE_JDP_BROADCAST="true" \
+    -e CRYOSTAT_ENABLE_JDP_BROADCAST="false" \
     -e CRYOSTAT_REPORT_GENERATOR="$CRYOSTAT_REPORT_GENERATOR" \
     -e CRYOSTAT_PLATFORM="$CRYOSTAT_PLATFORM" \
     -e CRYOSTAT_DISABLE_BUILTIN_DISCOVERY="$CRYOSTAT_DISABLE_BUILTIN_DISCOVERY" \

[andrewazores]

Retrying: https://github.com/cryostatio/cryostat/pull/1524