feat(FormGroup, FormSelect, TextInput, TextArea): Add warning state

[tlabaj]

What: Closes #4547

[patternfly-build]

PF4 preview: https://patternfly-react-pr-4554.surge.sh
A11y report: https://patternfly-react-pr-4554-coverage.surge.sh

[redallen]

LGTM. Core is going to need another bump before we promote (see patternfly/patternfly#3294) and the release notes will need to be updated as well.

[mcarrano]

@tlabaj just one thing I don't understand. On the FormSelect component, when I change the ValidatedOptions value in this line from error to warning the text below the field does not display correctly.

this.setState({ validated: ValidatedOptions.warning, invalidText: 'You must chose Three (thought that was obvious)' });

[mcoker]

Looks great!!

[mcarrano]

This line in the Validated example on Form Select is missing a "2" to get it to display the warning state when selecting the second option.

else if (value === '') { this.setState({ validated: ValidatedOptions.warning, helperText: 'You must select a value' });

Should be

else if (value === '2') { this.setState({ validated: ValidatedOptions.warning, helperText: 'You must select a value' });

[mcarrano]

Please disregard my earlier comment. I misunderstood how the example is intended to work. This is approved!

[redallen]

Still LGTM