Remove blocking 'wait' components

Summary

Removes components of the reconcile loop that wait for a condition before continuing. Instead, requeues the reconcile loop with a given delay. This ensures that the controller is not 'asleep' waiting for a condition, and can therefore still respond to changes in objects in the cluster (including changes to the GitLab CR).

Closes #660 (closed)

Testing

# Build Operator manifest
TAG=660-remove-wait task build_operator

# Deploy Operator
kubectl create ns gitlab-system
kubectl apply -f .build/operator.yaml

# Deploy GitLab
kubectl apply -f mygitlab.yaml -n gitlab-system

# Tail the logs, confirming that lines include 'not yet finished running'
stern -n gitlab-system -l control-plane=controller-manager