Revert "[lldb-vscode] Send Statistics Dump in terminated event"

This reverts commit c8a26f8c.

Returning full statistics result in "terminated" (DAP) event could result in delay in the UI when debugging from VSCode.

If the program run to exit and debug session terminates. The DAP event order will be: exited event --> terminateCommands --> terminated event --> disconnect request --> disconnect response.

The debugging UI in VSCode corresponds to "disconnect" request/response. If the terminated event is taking long to process, the IDE won't quit debugging UI until it's done.

For big binary (tested example has 29 GB of debug info), it can cause ~15s delay in terminated event itself. And the UI could take ~20s to reflect.

This may cause confusion in debug sessions. We should persuit a more lightweight return or other solution to return such info.