Move implicit-hie logic into vscode-haskell

[hasufell]

• https://github.com/haskell/haskell-language-server/blob/a7262964e00d65f79688825aafd77acb497c2c90/ghcide/session-loader/Development/IDE/Session.hs#L259
• https://hackage.haskell.org/package/implicit-hie-cradle-0.5.0.1/docs/src/Hie.Implicit.Cradle.html#loadImplicitHieCradle

I feel this is shady. It's better to move this into vscode-haskell, where we can prompt the user for a decision and then create hie.yaml for them.

HLS CI should have simple and predictable behavior. E.g. either use default cradle, always fall back to cabal or error out.

[July541]

Is it a good UX to give a prompt for a brand new haskeller to let them make a decision?

[hasufell]

Is it a good UX to give a prompt for a brand new haskeller to let them make a decision?

I question whether a brand new haskeller will end up with a project containing both stack.yaml and cabal.project and in case they do, they should absolutely be notified that this is an ambiguous situation.