We need to update the Integration Test pages to add a new field, where the user can determine which (if any) environment their app has access to, should be used as a template to configure the ephemeral environment the test executes in. We don't want to expose this to all users just yet, we want some more time to test the ephemeral environments feature, so we should feature flag the UI to only let users who know what they're doing be able to set this new field. 

Additionally, the Params field of the IntegrationTestScenario should be exposed to allow users to provide additional data that can be needed for testing of their deployed applications. The Params field consists of individual Tekton pipeline parameters which the Integration service can then propagate to integration testing pipelineRuns.

There should be a way for users to see provisioning errors when an ephemeral env encounters an error.

Changes:

• Add a feature flag to contain the integration test changes, so we can allow specific users to start testing this out
• When adding or editing an integration test, users should be able to select from a list of existing static environments, plus the option to say that no dedicated environment is needed.
• When adding or editing an integration test, users should be able to define additional parameters for their integration Tekton pipelines
• When viewing an integration test detail page, these fields should be visible

Considerations

• Ensure that integration test scenarios created without the feature flag (that don't set this environment field) still work as they used to, running in the user's namespace, without using a dedicated environment

Questions:

• Consider if the environment field is worth adding to the list view? 
  • My thought is we can skip this and keep it for the detail view
• How do our environment cards work today within an application in the side bar? With no changes, would ephemeral envs display or does that only show static envs?

Chat context: https://redhat-internal.slack.com/archives/C038DJAP7HR/p1682452535222469