[TRNT-4376] Move PostgreSQL config to global

[antgamdia]

Description

After we discovered some misalignment in the versions used for development (see trento-project/wanda#712 and trento-project/web#4290), we should consistently use a version for our database dependencies.

This PR chooses 17.5 as it is the default version being shipped in the OS version we base our images on. As of today, for 15 SP7 images, the PostgreSQL version is 17.5 (source). This PR, therefore, sets this version globally.

Edit: after some discussions, this PR simply prepares the chart for a future update; not does not perform the actual update.

To make it happen, we moved the image config to the globals section and, just for backwards compatibility, we set all the subcharts' values to this new version to avoid further inconsistencies.

Related # TRNT-4376

How was this tested?

CI

[arbulu89]

Looks good!
Important to test these changes really carefully as we are really close to release. Specially, a migration for an already deployed k3s with an older postgresql version. We need to be sure that the data that existed before is properly set in the new pod.
@antgamdia please, run those tests.

[antgamdia]

Important to test these changes really carefully as we are really close to release.

Yes, that's very true... maybe we can even postpone this change.

Specially, a migration for an already deployed k3s with an older postgresql version. We need to be sure that the data that existed before is properly set in the new pod.

Good idea. Ideally, we should have automated upgrade tests in our helm chart CI, though. But, yep, let me double-check manually. Thanks for the heads-up!

[antgamdia]

@arbulu89 , I've tracked the pg update separately; however, some of the changes herein performed can still be useful.
I've moved the PG image to global but I've kept the version set to 14, so that there are no functional changes.

> helm template .\charts\trento-server\  | grep "image:" | awk '{print $2}' | tr -d '"' | sort -u

busybox
docker.io/alpine:3.19
docker.io/rabbitmq:3.12.6-management-alpine
ghcr.io/trento-project/checks:1.2.0
ghcr.io/trento-project/trento-wanda:2.0.0
ghcr.io/trento-project/trento-web:3.0.0
k8s.gcr.io/kube-state-metrics/kube-state-metrics:v2.3.0
prom/pushgateway:v1.4.2
quay.io/prometheus/node-exporter:v1.3.0
quay.io/prometheus/prometheus:v2.53.1
registry.k8s.io/kubectl:v1.33.3
registry.suse.com/suse/nginx:1.27
registry.suse.com/suse/postgres:14

[arbulu89]

Nice!
Green light from my side.
Now, updating to a new version will be trivial!