Add notification when retrying trigger job

What does this MR do and why?

Behind the FF ci_recreate_downstream_pipeline, we allow use to retry their trigger jobs. This has the effect of spawning an new downstream pipeline. There are instances where while the new pipeline is getting created, the old one is no longer visible in the graph. For the MVC of this feature, showing a simple toast message that explains that a downstream pipeline might not yet be visible while being recreated.

Screenshots or screen recordings

Before	after

Video of the new behaviour

Screen_Recording_2023-02-23_at_9.43.04_AM

How to set up and validate locally

1. Turn on ci_recreate_downstream_pipeline FF through rails console.
2. Setup your GDK to have working runners https://docs.gitlab.com/runner/configuration/macos_setup.html
3. Write a CI/CD configuration with at least one downstream pipeline. Given that you have another repository (let's call it my-other-project) and that your username is root, something like this will work (Also make sure that the other project also has a functioning runner.):

trigger_job1:
  stage: build
  trigger: 'root/my-other-project'

1. Run a pipeline in the main project and wait for it to finish
2. Notice that the trigger job can be retried
3. Click on the retry button
4. Confirm that you want to retry the job
5. Notice the toast message appears

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #391877 (closed)