Fix potential race condition in progress dialog

[Megamouse]

m_text is new lol. It's used as storage for the const char* in the atomic object

[Megamouse]

Since we now use translatable strings instead of constexpr const char*

[elad335]

Since we now use translatable strings instead of constexpr const char*

This is a bug, scoped_progress_dialog object can be destroyed before the the progress_dialog access it, so m_text will be freed.

[Megamouse]

Oops. For some reason I thought the constructor resets the ptr when the thing goes out of scope. It's not hard to fix but I can only do it later

[elad335]

It's fixed in #16321, that was the point of the pr