fix(operator): Attempt to fix all the major issues present atm against the newest jenkins lts version (#784)

* fix(seed): fix #742, workaround #698
Original fix proposal: https://github.com/jenkinsci/kubernetes-operator/issues/742#issuecomment-1304398590

* fix(install-plugin.sh): fix #758, #739
* the fix was original attempted here:
  https://github.com/jenkinsci/kubernetes-operator/pull/764 but was not
  working correctly due to 2-3 additional changes which needed to be
  done
* removed the openshift check because the env is not mention anywhere
  and also the new jenkins-plugin-cli does not a specific command for
  openshift. Finally this does not make any sense in general, the only
  problem in ocp will be the user id that will be mapped to a random uid
  but that's another story. The command to install the plugins should
  remain the same across different k8s flavours.

* fix(doc/test): fix /usr/bin/tini in any doc and validation

* fix(jenkins): remove AdminWhitelistRule to avoid jvm stack trace, see: https://www.jenkins.io/doc/book/security/controller-isolation/jep-235/#api-compatibility

* fix(seed): fix seed img built on a previous jvm, fix #761

* fix(plugin): update the base plugin to work with the newest version of
jenkins:lts

* fix(run): fix #778

* fix(backup): add a trap to remove the tmp dir if the tar fail, also fix: #770

* test(chart): update chart values for testing, will revert before merge

* fix(configmap): leftover

* fix(tests): fix seed job test

* fix(e2e)

* fix(e2e): helm

* fix(operator): update the temporary img to reflect latests changes

* Fix Helm e2e tests

* add trap in case of unwanted exit and make shellcheck happy

* chore(plugin): update git ver to 5.0.0

* fix(backup): always force delete the backup directory

* chore(operator): update the temporary img to reflect latest changes

* chore(jenkins): upgrade jenkins latest lts

website/content/en/docs/Developer Guide/_index.md

@@ -132,7 +132,7 @@ items:
       - command:
         - bash
         - -c
-        - /var/jenkins/scripts/init.sh && exec /sbin/tini -s -- /usr/local/bin/jenkins.sh
+        - /var/jenkins/scripts/init.sh && exec /usr/bin/tini -s -- /usr/local/bin/jenkins.sh
         env:
         - name: JAVA_OPTS
           value: -XX:+UnlockExperimentalVMOptions -XX:+UseCGroupMemoryLimitForHeap