Inform LSP of supported code lenses (#973)

Provide the LSP with a mapping of supported code lenses to commands.
SourceKit-LSP will provide code lenses for running and debugging
applications with a @main function only when we configure the commands
we support.

Blocked by swiftlang/sourcekit-lsp#1556

Author: plemarquand

src/sourcekit-lsp/LanguageClientManager.ts

@@ -566,6 +566,12 @@ export class LanguageClientManager {
             errorHandler: new SourceKitLSPErrorHandler(5),
             initializationOptions: {
                 "workspace/peekDocuments": true, // workaround for client capability to handle `PeekDocumentsRequest`
+                "textDocument/codeLens": {
+                    supportedCommands: {
+                        "swift.run": "swift.run",
+                        "swift.debug": "swift.debug",
+                    },
+                },
             },
         };