Fix EditorFileDialog clears the file name on changing directory

[AThousandShips]

Regression from #51478, the change in that PR will clear the file when changing directory (which is undesirable, for example if you want to save the same name in a different directory), can't find any clear justification for the change in the PR, but I might have missed something, but in any case it breaks correct behavior relatively seriously, so what ever the reason for that change it has to be re-implemented with these effects in mind.

Might work correctly by moving the change to the cases below, but think this needs a dedicated investigation into what we actually want to accomplish here:

--- a/editor/gui/editor_file_dialog.cpp
+++ b/editor/gui/editor_file_dialog.cpp
@@ -264,17 +264,17 @@ void EditorFileDialog::update_dir() {
        }
        dir->set_text(dir_access->get_current_dir(false));

-       file->set_text("");
-
        // Disable "Open" button only when selecting file(s) mode.
        get_ok_button()->set_disabled(_is_open_should_be_disabled());
        switch (mode) {
                case FILE_MODE_OPEN_FILE:
                case FILE_MODE_OPEN_FILES:
+                       file->set_text("");
                        set_ok_button_text(TTR("Open"));
                        break;
                case FILE_MODE_OPEN_ANY:
                case FILE_MODE_OPEN_DIR:
+                       file->set_text("");
                        set_ok_button_text(TTR("Select Current Folder"));
                        break;
                case FILE_MODE_SAVE_FILE:

• Fixes: The scene's default save name missing #81225

[AThousandShips]

Pushed the alternative solution, which does the clearing when opening files, which makes sense

[starry-abyss]

The project import part (the source of the problematic line) seems to work good.

[akien-mga]

Thanks!

[AThousandShips]

Thank you!