Implement basic events for GitLab resources to communicate configuration errors

Adds a recorder which emits error events during the operator reconcile loop. This MR bubbles up checkConfig error events from the gitlab Helm chart. Users are then able to use and filter events to debug for GitLab resources, like so:

$ kubectl get events -n gitlab-system
...
25s         Warning   ConfigError                    gitlab/gitlab                                                Configuration error detected: template: gitlab/templates/NOTES.txt:115:3: executing "gitlab/templates/NOTES.txt" at <include "gitlab.checkConfig" .>: error calling include: template: gitlab/templates/_checkConfig.tpl:67:54: executing "gitlab.checkConfig" at <fail>: error calling fail: 
CONFIGURATION CHECKS:

gitaly:
    There must be one (and only one) storage named 'default'.

gitaly:
    external Gitaly repos needs to be specified if global.gitaly.enabled is not set
...

Closes #212 (closed)