sync: If a test case was added that reimplements another case, print the reimplemented UUID as well

Related to #44

For this example, assume that the `grains` case `10f45584-2fc3-4875-8ec6-666065d1163b` reimplements another case `b4bacc5a-3c12-43b6-ab17-d5ec78d70a15`

### As of configlet `4.0.0-beta.5`:

```console
$ configlet sync --tests --verbosity=detailed
[...]
[warn] grains: missing 2 test cases
- grains on square 3 (10f45584-2fc3-4875-8ec6-666065d1163b)
```

### Proposed

Put reimplemented case description and UUID on following line (for human readability)

```console
$ configlet sync --tests --verbosity=detailed
[...]
[warn] grains: missing 2 test cases
- grains on square 3 (10f45584-2fc3-4875-8ec6-666065d1163b)
- reimplements: square 3 grains (b4bacc5a-3c12-43b6-ab17-d5ec78d70a15)
```

### Alternative notation

Put reimplemented case UUID on same line (simpler to parse for scripts)

```console
$ configlet sync --tests --verbosity=detailed
[...]
[warn] grains: missing 2 test cases
- grains on square 3 (10f45584-2fc3-4875-8ec6-666065d1163b -> b4bacc5a-3c12-43b6-ab17-d5ec78d70a15)
```

Start by locating the code and tests that produce the `configlet sync --tests --verbosity=detailed` missing-test warning. Trace how reimplemented cases are represented and decide, with the issue discussion, which proposed notation to support. Done means the warning includes the reimplemented case description and UUID in the agreed format, with coverage for this output.

Written by the indexing model from the issue text.