Generate swiftinterface for symbol lookup
When a symbol definition returns it is in a swiftinterface file, create textual version of swiftinterface and return that in response.
Extend OpenInterface to also seatch for a symbol
Fix warning
Syntax changes after review
Move module name split into OpenInterfaceRequest
Use group names when running open interface request
Requested changes from PR
rename symbol to symbolUSR
Cleanup OpenInterfaceRequest.init
Fix tests
Added testDefinitionInSystemModuleInterface
Use SwiftPMPackage test module
Added version of buildAndIndex that includes system symbols
Merge buildAndIndexWithSystemSymbols with buildAndIndex
Added specific test project for system swiftinterface tests
Add multiple tests for various system modules
9ca89669b2