feat: Add branch option for postUpgradeCommands (#8725)

* Add branch option for postUpgradeCommands

* Put the for loop back for async

* Fix tests & add documentation

* Change execution mode dependency to update

* Move postUpgradeCommand execution to seperate file

* Fix return time of upgradeTaskExecuter

* Fix test

* Finished new mode and added test

* Remove .only

* Remove defensive coding to make codecov happy

* Give inconfig a proper type

* Another missing type

* Fix typo in allowPostUpgradeCommandTemplating option description

Co-authored-by: Michael Kriese <michael.kriese@visualon.de>

* Move to 1 postUpgradeCommandExecutor call

* Appease the import order rule gods

* Refactor more

* Okay now it should be done

* Fix bug

* Import order rule

* Change import to a type import

* Also return artifacterrors

* Apply suggestions from code review

Co-authored-by: Michael Kriese <michael.kriese@visualon.de>

* Move checking if postUpgradeCommands can run

* remove unused import

* Fix prettier error

* Call getAdminConfig once

* Apply suggestions from code review

Co-authored-by: Michael Kriese <michael.kriese@visualon.de>

* Change type name to EnsurePrResult

* Update lib/workers/branch/index.spec.ts

Co-authored-by: Michael Kriese <michael.kriese@visualon.de>

* Apply suggestions from code review

Co-authored-by: Michael Kriese <michael.kriese@visualon.de>

* Fix enum imports

Co-authored-by: Carlin St Pierre <cstpierre@atlassian.com>
Co-authored-by: Michael Kriese <michael.kriese@visualon.de>