Selection Modifier Keys Only Applies During Selecting

[UnAngelito]

Pixelorama version:
1.1.7-rc2

Where did you download Pixelorama from?
Nightly

OS/device including version:
Windows

Issue description:
Modifier keys (Shift, Control...) are the extra buttons that are pressed to modify the operation of a tool. I can see that only the Selection Tool doesn't apply the "modification" unless is pressed again. This means that "selection tool" doesn't apply modifications if key modifiers were pressed before.

Steps to reproduce:

1. Press a modifier key (Shift, CTRL...) to modify a selection (with Shift makes a square, with CTRL the selection is "centered" instead of "from the corner")
2. Make a selection
3. Press the modifier key again to apply the modifier