[Feature Request]: Add "Move to Schema…" to the object context menu in the Database Projects tree

## Feature Description

Add a "Move to Schema…" context menu (right-click) action on object nodes in the Database Projects tree. Today, Move to Schema is only available from the editor (Refactor… / code action) when a SQL file is open and the cursor is on the object. It would be helpful to also invoke it directly from the project tree by right-clicking an object (table, view, stored procedure, function, etc.) and choosing "Move to Schema…", which would show the same schema picker and refactor preview.

## Problem and Motivation

Currently, to move an object to another schema I have to open its `.sql` file, place the cursor on the object, and use the Refactor menu. When working in the Database Projects tree, it's more natural to act on the object node directly without opening the file first. Adding the action to the tree's right-click menu would:

- Make the feature discoverable where users already manage project objects.
- Save the open-file + position-cursor steps.
- Match the way other object actions are exposed in the tree.

The action should reuse the existing Move to Schema flow (schema picker + refactor preview + refactorlog update), just triggered from the tree node instead of the editor cursor.

## Related Area

- SQL Database projects

## Confirmation

- [x] I have searched existing feature requests and couldn't find a match
- [ ] I want to help implement this feature