Add phrase button to wysiwyg.

[cruzanmo]

For our purposes a "phrase" is a group of one or more words.

This PR allows any component to add a phrase button to the wysiwyg behavior.

e.g.

text:
  _has:
    -
      fn: wysiwyg
      buttons:
        - bold
        - italic
        - strikethrough
        - anchor
        - phrase:
            aria: annotate
            name: annotate
            contentDefault: A¹
            phraseClassList: ['clay-annotated'] # adds this class to the span
            phraseTagName: span

https://trello.com/c/EUYTk5fh/13-l-new-article-component-footnotes

[davidandrewfrey]

Might be easier to read if this function was named something like hasSelectionPhrase to convey a boolean return value.

[coveralls]

Coverage decreased (-0.2%) to 79.184% when pulling 4c46dbb on phrases into f89c1c9 on master.

[davidandrewfrey]

⭐ ⭐ ⭐ ⭐ ⭐

[coveralls]

Coverage decreased (-0.2%) to 79.184% when pulling 47c70c0 on phrases into f89c1c9 on master.

[nelsonpecora]

👍