Ghost selection when working with several tabs

Nobody has claimed this yet.

## Description

data stored in the selection buffer might not be displayed in a few specific scenarii, misleading the user into thinking it's lost

### Steps to reproduce the bug

1. previewing a transformation of the selection
2. opening a new image (ctrl+t)
3. changing the active tool to a tool which isn't a selection tool, nor another transformation tool (eg the pencil)
4. coming back to the initial image

result:

- it keeps the pencil as the active tool window-wide, which includes the tab of the initially edited image (correct?)
- it doesn't deselect the area (correct? incorrect?)
- but the app doesn't know how to handle the selection buffer when the tool is the pencil, so it displays a transparent area missing pixels, as if the data was lost
- yet the data is not lost, if you enable a selection tool it's displayed again (correct)
- but the transformation has been cancelled (incorrect?)

## System

- Device (desktop computer/tablet/phone/...): any
- OS: any
- Desktop environment: any
- Package format: any
- App version: 1.1.x

Reproduce the issue using the listed multi-tab steps, including previewing a selection transformation, opening another image, switching to the pencil, and returning to the initial image. Determine the intended selection and transformation behavior, then verify that the selection data is displayed correctly and is not unexpectedly lost or cancelled.

Written by the indexing model from the issue text.