Cucumber data table

[ron-brosh]

Based on the Cucumber documentation, there's a way to support tabular data using a class called DataTable.
That class can return the data to the consumer in three ways:

1. list of lists
2. list of maps
3. custom table transformer

This PR adds the DataTable model with the first two use cases.

• DataTable is also available as a widget in the material package so in our context it's prefixed with the import's bdd:

import 'package:bdd_widget_test/src/data_table.dart' as bdd;

• Added unit tests
• Tested generated feature file
• 100% coverage on new changes

[olexale]

Hey @ron-brosh,
Thanks for the PR. I made a few suggestions and comments, please review.

[olexale]

Types for all other lines from features files are described in LineType enum. Are there any reason why the data table line can not follow the same pattern?

[ron-brosh]

Besides _lineTypeFromString which needs the next lines in order to determine the dataTable type, the
step enum is used in the generation logic which fails the tests when I add the new type.
It also adds a lot of boilerplate (will have to be repeated in multiple places):

if(type = LineType.step || type == LineType.dataTable)

LineType enum describes unique lines that can be map to those types.
A cucumber data table is determined by the combination of a step and examples.
I'll be happy to explore any proposal that might simplify and keep the existing convention though.

[ron-brosh]

Added a new enum value dataTableStep and modified the StepFile.create to accept the domain model BDD line instead of its internal implementation details.