Use implicit-hie cradle for multi cradle config

[Avi-D-coder]

People routinely get confused when writing a hie.yaml. implicit-hie can generate correct hie.yaml files or in this case hie-bios Cradles for almost all stack and cabal projects. It's failures are graceful; ghcide will still work on most files, and where it does not the hie-bios no cradle matched error message is decipherable.

It has very few dependencies, in the future it may use cabal-parsers to handle common stanzas and conditionals, but this dependency would be behind a flag if ghcide uses implicit-hie.

This is the exact same issue as #138 and #38, but for ghcide.

[ndmitchell]

Over time the plan is to tell more and more people to use HLS, and consider Ghcide to be a dependency to that. I'd be inclined to update the docs to suggest running implicit-hie manually for users, and to suggest using HLS, but keep Ghcide more "pure". However, that's just my view, others may feel differently.