feature: Use flatpak blueprint

[ravener]

I suggest supporting the blueprint compiler being found in the sources and then integrating with vscode-blueprint so that the blueprint language server can detect newer widgets available in the flatpak SDK.

[ravener]

bodil/vscode-blueprint#4 is a potential way to solve it, seems like the custom blueprint command setting does not take arguments but a single executable, but creating a script to execute the flatpak blueprint seems to work fine, finally I get better intellisense.