Enable rbs collection support

[pocke]

This patch adds rbs collection feature to TypeProf.
See ruby/rbs#589 for more details of rbs collection.

TypeProf will behave the following by this patch.

• If rbs_collection.yaml exists in the current directory, TypeProf loads libraries' RBSs from the config file.
• If --collection PATH option is specified, TypeProf loads libraries' RBSs from the specified file.
• If --no-collection option is specified, Typeprof ignores rbs_collection.yaml.
• If rbs_collection.yaml doesn't exist and no options are specified, TypeProf does nothing about rbs collection feature.

The option names are the exactly same as rbs command's options.

Testing

I've confirmed the feature works with the following procedure.

1. put the following files
   • Gemfile

     source 'https://rubygems.org'
     
     gem 'ast'

   • Gemfile.lock

     GEM
       remote: https://rubygems.org/
       specs:
         ast (2.4.2)
     
     PLATFORMS
       x86_64-linux
     
     DEPENDENCIES
       ast
     
     BUNDLED WITH
        2.2.27
     

   • rbs_collection.yaml

     # Download sources
     sources:
       - name: ruby/gem_rbs_collection
         remote: https://github.com/ruby/gem_rbs_collection.git
         revision: main
         repo_dir: gems
     
     # A directory to install the downloaded RBSs
     path: .gem_rbs_collection
     
     gems:
       # Skip loading rbs gem's RBS.
       # It's unnecessary if you don't use rbs as a library.
       - name: rbs
         ignore: true
     

   • test.rb

     require 'ast'
     
     class C
       def x(node)
         node.children
       end
     end
     
     node = AST::Node.new(:x, [:foo, 42])
     C.new.x node
     

2. Run rbs collection install to install RBS for ast gem
3. Run typeprof test.rb
   • It displays the following result.

     $ typeprof test.rb
     warning: rbs collection is experimental, and the behavior may change until RBS v2.0
     # TypeProf 0.15.3
     
     # Classes
     class C
       def x: (AST::Node node) -> Array[untyped]
     end
     

   • It is aware of ast gem's type 💪