Allow multi-select the ram view

Feature Request: Multi-select PBS elements in RAM View

Summary:
Add the ability for users to select one or multiple PBS elements directly within the RAM View so they can perform bulk actions such as export or delete on the selected set, rather than acting on items one by one.

Problem Statement:
In the current RAM View, users cannot easily select multiple specific PBS elements to perform common operations in bulk. When they need to export or delete multiple items, they must handle each element individually or rely on inefficient workarounds. This is especially problematic when working with large, complex PBS structures, leading to extra time, higher risk of mistakes, and frustration for users who regularly manage subsets of PBS elements.

Proposed Solution:
Introduce multi-select capabilities in the RAM View that allow users to select one or many PBS elements at once (e.g., via checkboxes, shift-click, or control/command-click).
Support bulk actions on the selected PBS elements, starting with:

• Export selected PBS elements

• Delete selected PBS elements

Ensure that:

• The selection is clearly visible and easy to modify (add/remove items from the selection).

• Bulk delete actions require confirmation to prevent accidental data loss.

• Bulk export respects existing export formats and includes only the selected PBS elements and their necessary attributes/relationships.

• The selection state is preserved while users scroll or navigate within the RAM View, as long as they remain on the same context.

Benefits:

• Saves significant time by allowing users to manage multiple PBS elements in a single operation instead of repeating actions per item.

• Reduces the likelihood of user errors when exporting or deleting many elements.

• Improves usability of the RAM View for users working with large or complex PBS structures.

• Increases overall user satisfaction by aligning the tool with common multi-selection patterns found in other applications.