(#1188) Rows measure greedy

[nils-a]

fixes #1188

• I have read the Contribution Guidelines
• I have commented on the issue above and discussed the intended changes
• A maintainer has signed off on the changes and the issue was assigned to me
• All newly added code is adequately covered by tests
• All existing tests are still running without errors
• The documentation was modified to reflect the changes OR no documentation changes are required.

Changes

The Rows widget was measuring the required space by using the min of the minimal content width and the mix of the maximal content width:

spectre.console/src/Spectre.Console/Widgets/Rows.cs

Lines 40 to 46 in e2a6748

	var measurements = _children.Select(c => c.Measure(options, maxWidth)).ToArray();
	if (measurements.Length > 0)
	{
	return new Measurement(
	measurements.Min(c => c.Min),
	measurements.Min(c => c.Max));
	}

The new calculation is "greedy" by always choosing the max value.

[patriksvensson]

LGTM!