pipeline promotion enhacements

[enekofb]

During the RFC discussion there have been different features suggested that should consider for further iterations.

This issue lists them for intaking purposes

1. For a given PR raised by wge, as developer i want to be able to navigate both ways (from wge <-> git provider) with the context information required in order to act on the PR (merge or reject) where possible.

2. as app team using wge pipelines for my application, I want to understand how can i automatically merge created PRs, so I dont need to manually approve it under certain conditions

3. as app team, I want to define whether promotions should create or update a pr when more than one change has been promoted but not merged. for example https://github.com/peter-evans/create-pull-request/blob/main/src/create-or-update-branch.ts

4. what to do when there is an urgent fix that we need to release and we cannot wait for the pipeline to run through all the environments

[sympatheticmoose]

As these are very separate things, I'm going to break down into tasks and then close this particular issue assuming you're ok with that @enekofb ?

1. I think is related to a broader topic of providing more context for the approver - for which i've raised Spike: appropriate context for the promotion approver #1851
2. This should be sample documentation, ideally referencing existing material - added Extend documentation for auto-merge PRs #1852 and we should address as part of 0.2
3. Yes, this would be a good enhancement, but is not a priority right now - added Provide option to edit PRs or create new #1853
4. For one, the pipeline is not the ONLY way to push the new version, the user could manually edit the helmrelease(s) for a given environment. However, I do think a manual invocation of promoting is worth exploring (particularly when paired with a default strategy of waiting for all deployment targets within an environment to report success) - added Ability to manually invoke promotion to a given environment #1854