Update standalone extension deployment

[silvi-t]

Summary

Kuadrant/helm-charts-olm#114 moves standalone Kuadrant extensions (e.g. pipeline-policy) out of the operator CSV patch and into their own installable Helm chart, charts/kuadrant-extensions, deployed as a separate release with configurable extensionsImage, extensionsNamespace, extensionsName, and extensionsToken values.

Once that PR merges, this repo's CI needs to add support for deploying extensions using the new chart.

Current state

• Extension deployment is currently disabled in this repo's CI.
• There is no Tekton task or pipeline wiring yet for deploying extensions via Helm.

What needs to happen (once helm-charts-olm#114 merges)

• Add a Tekton task that deploys extensions using the new charts/kuadrant-extensions chart (or the equivalent install.sh -e / uninstall.sh flow it documents).
• Map the task's parameters to the new chart values (extensionsImage, extensionsNamespace, extensionsName, extensionsToken).
• Wire the task into all pipelines that deploy Kuadrant so extension deployment runs as part of the normal pipeline flow when an extensions image is configured.