[BUG] can't open slnf files from recent list

[MagicAndre1981]

Describe the bug

I can't open a filtered sln file from recent list

To Reproduce

1. clone Xamarin.Forms repro
2. open .Xamarin.Forms.Android.slnf and close the solution
3. try to open the Xamarin.Forms.Android entry from recent projects again
4. See error

Expected behavior

I can open the slnf again

Screenshots

Desktop (please complete the following information):

• OS: Windows 11 23H2
• VS2022 17.8.x

Additional context

StartPage+ doesn't know the slnf format and shows a ? in the recent list where you would see sln or csproj icons

[MagicAndre1981]

ok, I added a fix for this in #37