Refactor Annotation creation

[danfsd]

Imitate the Highlight creation process to Annotation:

• #js CREATE annotateString() function imitating highlightString() becomes , create the <marker ...></marker>{content} instead of creating a <highlight ...>{content}</highlight> tag.
• #swift ADAPT FolioReaderWebView.createAnnotation() function imitating FolioReaderWebView.createHighlight.
• #swift CREATE Highlight+Helper.matchAnnotation() function imitating Highlight+Helper.matchHighlight.
• Inserting <marker> before actually creating the annotation (closing the annotation modal without saving) will make the annotation marker to continue there.

Also VERIFY if the current strategy to get content from the HTML is valid or if we should return to the DEFAULT way.