feat(builtin): add a DeclarationInfo provider
feat(builtin): add a DeclarationInfo provider

This gives us a principled way for rules to generate and consume TypeScript typings

alexeagle/rules_nodejs,alexeagle/rules_nodejs,alexeagle/rules_nodejs,bazelbuild/rules_nodejs,bazelbuild/rules_nodejs,bazelbuild/rules_nodejs,bazelbuild/rules_nodejs,alexeagle/rules_nodejs,bazelbuild/rules_nodejs