Alt-Numpad shortcuts active when using Alt-codes

Summary:

When using keyboard Alt codes to insert special characters, related keyboard shortcuts are activated

Steps to reproduce:

• open Inkscape
• Create a new text object (F8)
• Insert a special character by typing its alt code.
  • Example: Depress the "Alt" key, type 0150 on the number pad, then release the "Alt" key, to insert an en-dash (–)

What happened?

• The required character was inserted (as expected)
• The "Alt-NumPad5" shortcut (toggle greyscale filter) was also triggered
• Turning off the greyscale filter with Alt-NumPad5 inserts a ♣ symbol to the text area

What should have happened?

Alt-numpat shortcuts should be disabled when editing a text area – or at a minimum, when an alt-code sequence is triggered

Version info

Inkscape 1.3 (0e150ed6c4, 2023-07-21)

    GLib version:     2.76.4
    GTK version:      3.24.38
    glibmm version:   2.66.6
    gtkmm version:    3.24.7
    libxml2 version:  2.11.4
    libxslt version:  1.1.38
    Cairo version:    1.17.7
    Pango version:    1.50.14
    HarfBuzz version: 8.0.1

    OS version:       Windows 10 22H2