Add autofix to block-closing-brace-empty-line-before

[boccob]

Which issue, if any, is this issue related to?

Closes #3614

Is there anything in the PR that needs further explanation?

ex.

• option: always-multi-line

  code:

  a {
    color: pink;
  }

  fixed:

  a {
    color: pink;
  
  }

• option: never

  code:

  a {
    color: pink;
  
  }

  fixed:

  a {
    color: pink;   
  }

• option: ["never", { except: ["after-closing-brace"] }]

  code:

  @media print {
  
    a {
      color: aquamarine;
    }
  
    b {
      color: hotpink;
    }
  }

  fixed:

  @media print {
  
    a {
      color: aquamarine;
    }
  
    b {
      color: hotpink;
    }
  
  }

• option: ["always-multi-line", { except: ["after-closing-brace"] }]

  code:

  @media print {
  
    a {
      color: aquamarine;
  
    }
  
    b {
      color: hotpink;
  
    }
  
  }

  fixed:

  @media print {
  
    a {
      color: aquamarine;
  
    }
  
    b {
      color: hotpink;
  
    }
  }

[jeddy3]

@boccob Thanks. LGTM.

@ota-meshi Are you able to cast a 2nd pair of eyes over this?

[jeddy3]

• Added: block-closing-brace-empty-line-before autofix (#3598).