#4068: Provide number widget

[stefan-korn]

fixes #4068

• [ ] Test coverage exists
• [ ] Documentation exists

QA Steps

• [ ] Add manual QA steps in checklist format for a reviewer to perform to confirm that the feature or fix is working. Include as much details as possible so that the reviewer doesn't lose time figuring out how to perform steps.

[janette]

@stefan-korn this would need test coverage before it can be merged.

[dafeder]

@stefan-korn are you able to add some coverage? The easiest thing would probably be to add a number field to Drupal\Tests\json_form_widget\Unit\JsonFormBuilderTest

[stefan-korn]

@dafeder : I addressed your comments.

Regarding "number" in the schema. I wasn't aware that there is the integer field. It is only used once in the data-dictionary.json I suppose and we do not need data dictionary right now, so I missed that.

Should the schema be configurable about step, min and max? That way no widget "number" would be needed at all?

[dafeder]

@stefan-korn re-thinking this I think the "number" field in the schema itself can be dealt with separately, should not be a blocker for this. I did a new PR from this that hits the test coverage, closing this in favor of #4215. Thanks!