…ort`

This makes it more practical to print objects containing such reports,
e.g. `[report]`.

Closes #1293

…ort`

This makes it more practical to print objects containing such reports,
e.g. `[report]`.

Closes #1293

#1286)

- [x] Rename to `ComparisonReport`
- [x] Rebase on top of #1239 and adapt
- [x] Raise if `report.metrics.accuracy(data_source="train")` is called
with at least one EstimatorReport that does not have training data
- [x] Test
- [x] Docstrings
    - [x] MetricsAccessor
- [x] Move index column "#0" in front of each metric
- [x] Pass report names in comparator
- [ ]  ~Update plots legend~ see #1309 
- The actual `RocCurveDisplay` needs a full refactor to be splitted by
use-case: estimator report, cross-validation report and finally
comparison report. In each of these use-cases, there is two scenarios
with binary classification and multi-class classification. Otherwise, it
will be unmaintainable.
- [ ] ~Investigate missing metrics in `report_metrics`~ **(deferred to
future PR)**
- The logic is split between `report_metrics` and `available_if`; it
should be merged (ideally everything in `available_if`?)
- [ ] ~Refactor to make `CrossValidationReport` depend on it~
**(deferred to future PR)**
- [x] ~Change EstimatorReport `repr`?~ Issue
#1293

Closes #1245 

Co-authored-by: Auguste <[email protected]>
Co-authored-by: Sylvain Combettes <[email protected]>