Ability to edit customer journey data

Feature description

As an admin, I want the ability to change the start date of every steps in the customer journey.

Use cases

Benefits (For whom and why.)

Stakeholder (Person who should verify the use case acceptance criteria)

Requirements (checklist preferred)

Engineer checklist:

• Under the user details page/ customer journey, add the ability to edit the start date for each steps.

/cc @doreeno , @minza