[Change Requests] - Creator-only "Edit" action on a declined change request

Description

Context

On a declined change request, its creator should get an "Edit" option that takes them to the edit form pre-filled with what they originally proposed, lets them adjust it, and resubmits, instead of rebuilding a new CR by hand. Only the creator sees it, and only when the CR is declined.

Task

Add an "Edit" action to the change request's actions dropdown, shown only to the creator of a declined CR, that routes to the edit project/work-package form pre-filled with the original proposed changes and resubmits through the usual flow.

Acceptance Criteria

• The "Edit" action appears only when the current user is the CR's creator and the CR was declined.
• Clicking it opens the edit project/WP form pre-filled with the CR's original proposed changes.
• The user goes through the normal "why" text step and submits, which calls the resubmit endpoint.

Start by locating the change request actions dropdown, the existing resubmit endpoint, and the project/work-package edit form and normal “why” step. Trace how declined requests and their original proposed changes are represented; done means the creator alone sees Edit for declined requests, the form is pre-filled, and the normal flow resubmits successfully.