UVE: Remove duplicate dialog instances

[rjvelazco]

Background

DotEmaDialogComponent is instantiated in both EditEmaEditorComponent and DotEmaShellComponent, leading to duplicated state, inconsistent UX, and extra bundle weight. We can centralize dialog control with a shared Angular service.

 Task

Remove the two separate instances of DotEmaDialogComponent, there is one inside DotEmaShellComponent and another inside EditEmaEditorComponent. We need to centralize the logic in one component.

Proposed Objective

Same as Parent Issue

Proposed Priority

Priority 3 - Average

 Acceptance Criteria

• Single dialog instance exists in the DOM.
• EditEmaEditorComponent and DotEmaShellComponent have one reference of the same dialog