Warn users about font replacement in property panel

When importing a project from Figma it is very easy to miss that the font you used in your design is not part of the project.

After import the font property in the editor will show you that the font you used in Figma is the one selected in qtds, even though the font is not installed and not used.

Only by checking the output logs can you see that the font was replaced.

We should check the font is available when we import and if not show a warning, we should also not show in the property panel that a font is selected that is not actually there. Instead it should indicated what replacement font is being used and provide a warning icon in the special icon column with a tooltip to clarify this is a replacement font.

Ideally we would provide a way to install and update this font for the whole project by tracking which font was replaced and updating all instances when the correct font is added.

This is causing problems because when fonts are similar but not the same it causes text positioning, line breaks and wrapping to look broken from the original Figma design and is hard to see why things are not looking correct, leading users to assume the Figma bridge is at fault here.