[Feature] Support for ephemeral environment deployments

[oanasc]

Is your feature request related to a problem? Please describe.

From every git branch we deploy an ephemeral environment in our develop k8s cluster. The application name and components require an additional suffix appended in the name in order to deploy several versions of the same application with a unique name and not clash with one another, in our case we use the branch name to generate a suffix.

Describe the solution you'd like

1. A possible solution could involve allowing a new variable nameSuffix in the metadata which if present will be automatically appended to all the component, traits, workflows, policy names and to the context.name and context.appName

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: webwithsa
  nameSuffix: mybranch
  namespace: vela-dev
spec:{}

2. Another option is to implement the same nameSuffix and allow cue templating in the application.yaml so we can use the context to generate the final name

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: webwithsa
  nameSuffix: mybranch
  namespace: vela-dev
spec:
  components:
    - name: component1 + context.nameSuffix
      type: webservice
      properties:
        image: oamdev/hello-world

If possible option 2 would be better as there could be alot more places the suffix needs to be used like an application with env variables pointing to another component service name, or a database name.

Describe alternatives you've considered
I tested the sub app model where a app yaml is defined as a component, and although that could work it creates an additional application that is confusing for end users

Additional context