Limit cases where "required" attribute is used on checkboxes

[LucianBuzzo]

Fixes #338

If the "required" attribute is applied to a checkbox, then HTML5
validation will only pass if the checkbox is ticked. This is at odds
with the JSON schema definition of "required" that simply requires that
the key exists.

This PR will make it so that the "required" HTML5 attribute will only be
applied if the schema uses { const: true } or { enum: [ true ] }.

Signed-off-by: Lucian lucian.buzzo@gmail.com

Reasons for making this change

[Please describe them here]

If this is related to existing tickets, include links to them as well.

Checklist

• I'm updating documentation
  • I've checked the rendering of the Markdown text I've added
• I'm adding or updating code
  • I've added and/or updated tests
  • I've updated docs if needed
  • I've run npm run cs-format on my branch to conform my code to prettier coding style
• I'm adding a new feature
  • I've updated the playground with an example use of the feature

[epicfaace]

@LucianBuzzo What about this schema?

{
      "type": "boolean",
      "oneOf": [
        {
          "const": true
        }
      ]
}

[epicfaace]

@LucianBuzzo What about this schema?

{
      "type": "boolean",
      "oneOf": [
        {
          "const": true
        }
      ]
}

@LucianBuzzo Just bumping this.

[LucianBuzzo]

@epicfaace Thanks for the reminder, I'll hopefully get time to add this case this afternoon

[LucianBuzzo]

@epicfaace I've added additional logic for handling cases where anyOf, oneOf and allOf would require the field to be true

[epicfaace]

Looks great!