Use shorter library IDs and names

[annagrin]

Currently LibraryRefs returned from getIsolate contain the library url three times - as Id, name, and uri. Isolate object contains a list of libraries that reaches a 1.7Mb for the ACX demo gallery.

Shortening the Id and the name might make the isolate smaller, take less memory in dwds and DevTools internal state, and even reduce the DevTools IPL. Might want to investigate and copy what VM does.

Example:

"libraries": [
    {
        "type": "@Library",
        "id": "dart:_runtime",
        "name": "dart:_runtime",
        "uri": "dart:_runtime"
    },
    ...
    {
        "type": "@Library",
        "id": "package:collection/src/combined_wrappers/combined_iterator.dart",
        "name": "package:collection/src/combined_wrappers/combined_iterator.dart",
        "uri": "package:collection/src/combined_wrappers/combined_iterator.dart"
     },
  ]