feat: update padded-blocks for class static blocks

[mdjermanovic]

Prerequisites checklist

• I have read the contributing guidelines.

What is the purpose of this pull request? (put an "X" next to an item)

[ ] Documentation update
[ ] Bug fix (template)
[ ] New rule (template)
[x] Changes an existing rule (template)
[ ] Add autofixing to a rule
[ ] Add a CLI option
[ ] Add something to the core
[ ] Other, please explain:

Refs #15016, fixes padded-blocks.

What changes did you make? (Give an overview)

Updated the padded-blocks rule to apply to class static blocks.

/* eslint padded-blocks: ["error", "always"] */

if (foo) { // applies to block statements
  bar();
}

class C {
  
  method() { // applies to function and method bodies
    bar();
  }
  
  static { // should apply to class static blocks, too
    bar();
  }
  
}

When the object option is used, the existing "blocks" applies to class static blocks, as it already applies to both block statements and function bodies.

/* eslint padded-blocks: ["error", { "blocks": "always" }] */

if (foo) { // applies to block statements
  bar();
}

class C {
  
  method() { // applies to function and method bodies
    bar();
  }
  
  static { // should apply to class static blocks, too
    bar();
  }
  
}

Is there anything you'd like reviewers to focus on?

[nzakas]

LGTM