LinkButton's text is not automatically translated (unlike Button)

[Calinou]

Godot version

3.3.3.stable, 4.0.dev

System information

Fedora 34, GeForce GTX 1080 (NVIDIA 470.57.02)

Issue description

LinkButton's text is not automatically translated, unlike Button's text.

As a workaround, you can use a script to set the button's text wrapped with a tr() call.

This was originally reported in #34050 (comment).

This is because Button's set_text() logic should be copied into LinkButton's:

https://github.com/godotengine/godot/blob/3.x/scene/gui/button.cpp#L242-L251

https://github.com/godotengine/godot/blob/3.x/scene/gui/link_button.cpp#L33-L37

The same should also be done in the master branch.

Steps to reproduce

• Create a Button node and set some text to it.
• Create a LinkButton node and set some text to it.
• Translate both their texts using a CSV or PO file.
• Notice that only the Button's text is changed.

Minimal reproduction project

No response