cabal cradle: Allow list of targets

[mpickering]

When using a version of cabal which supports the multi repl then it is useful to be able to pass a list of targets to cabal repl when setting up GHC options. At the moment only one target seems to be supported because cabal repl only accepts one target.

[michaelpj]

I think this is done?

[fendor]

Not quite, as you cant write, for example:

cradle:
  cabal:
    component: ["lib:hie-bios", "exe:hie-bios"]

to load only these two components. You can only provide a single target, such as all, which will load all enabled targets.