"Link a page"-dialog in a timeline should be alphabetically sorted and not close automatically

### Steps to reproduce the behavior

1. Go to https://www.notebook.ai/plan/timelines/new
2. Click on "Link a page"

### Current behavior

A dialog pops up. This dialog lists different pages grouped by type and sorted by id, e.g.:


When a page is selected, the dialog closes. To link more than one page, "Link a page" must be clicked again to re-open the dialog.

### Expected behavior

First, I would suggest to sort by name and not by ID.

Also, I'd suggest to keep the dialog open after clicking on an entry. This would enable users to link multiple pages without clicking "Link a page" multiple times. The dialog already closes automatically when a user clicks "outside".

Start at the timeline creation page at https://www.notebook.ai/plan/timelines/new and open the "Link a page" dialog. Trace how entries are ordered and how selection closes the dialog. Done means pages are sorted by name within their groups and selecting an entry leaves the dialog open for additional links while outside clicks still close it.

Written by the indexing model from the issue text.