Helm charts should not use floating image tags by default

[MBrinks2239]

Describe the issue
Helm charts should not use a floating docker tag in their values. This can make deployments change and update without being intended to.
The PullPolicy can help against issues with this but does not fully protect you.

To Reproduce

1. Deploy the helm chart with the default setting (specifically PullPolicy set to IfNotPresent and tag: dev).
2. Wait for tag dev to be updated on the docker registry.
3. Add a new node to your cluster (that does not have the old dev tag images loaded).
4. Drain a node running harbor pods.

Actual result
The new pod will pull the latest harbor image that is ahead in version of the other services.

Expected behavior
After deployment, Harbor app version stays the same.

Additional context
In my case, my database got migrated to the new version while the harbor-core version was still behind, resulting in a crash-looping harbor pod.

My suggested fix for this is to make image tag's default to the chart app version instead of a floating tag.
Another fix would be to hard code all app versions for all containers in the default values.

I will open a PR containing my suggested fix of making tag's default to the chart app version.