### Description

Evals that introduce aliased can be simplified by extracting them into a project (and thus signaling there's no underlying processing).

The following eval:
`eval x = a + 1, y = x, z = y + 1, y = z, w = y + 1`
can be converted into:
`eval x = a + 1, z = a + 1 + 1, w = a + 1 + 1 | project x, z, z as y, w`

This helps fuse the project with other projections/aggs downstream.
x-pack/plugin/esql/qa/testFixtures/src/main/java/org/elasticsearch/xpack/esql/CsvTestUtils.java
);
                        }
                    }
                    
                    else {
                        if (entries.length != columns.length) {
                            throw new IllegalArgumentException(
                                format(
                                    "Error line [{}]: Incorrect number of entries; expected [{}] but found [{}]",
                                    lineNumber,
                                    columns.length,
                                    entries.length
                                )
                            );
                        }
                        for (int i = 0; i < entries.length; i++) {
                            var entry = entries[i];
                            try {
                                columns[i].append(entry);
                            } catch (Exception e) {
                                throw new IllegalArgumentException(
                                    format("Error line [{}]: Cannot parse entry [{}] with value [{}]", lineNumber, i + 1, entry),
                                    e
                                );
                            }
                        }
                    }
                }
                lineNumber++;
            }