Preserve entity selection when filtering/searching

[Copilot]

Entity search/filter was clearing all checked items, forcing users to re-select entities after each search operation.

Changes

Modified FillListEntities() to preserve checked state across ListView updates:

• Capture checked entity SchemaNames before clearing items
• Restore checked state when repopulating with filtered results

private void FillListEntities(List<Entities> items)
{
    // Save checked state before clearing
    var checkedSchemaNames = new HashSet<string>();
    foreach (ListViewItem item in lvEntities.Items)
    {
        if (item.Checked)
            checkedSchemaNames.Add(item.Tag.ToString());
    }

    lvEntities.Items.Clear();
    lvEntities.BeginUpdate();
    foreach (var item in items)
    {
        var listViewItem = new ListViewItem { /* ... */ };
        
        // Restore checked state if previously checked
        if (checkedSchemaNames.Contains(item.SchemaName))
            listViewItem.Checked = true;
            
        lvEntities.Items.Add(listViewItem);
    }
    lvEntities.EndUpdate();
}

Users can now build entity collections incrementally while searching.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>When searching for entities, selection is cleared</issue_title>
<issue_description>When using the search function for entities, selection is cleared. Instead, I would like selected entities stay selected so that I can get a collection of entities selected quickly. </issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes When searching for entities, selection is cleared #36

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[MscrmTools]

The checkedSchemaNames should be updated to remove the item.SchemaName when an item is unchecked