GUACAMOLE-1969: Display clipboard history within recordings.

[aleitner]

Add inline clipboard display to keystroke log Merge clipboard events chronologically with key events in the recording player's keystroke log. Clipboard content displays inline as [Clipboard: content] at the timestamp when it was captured by the last key event or updated externally and timestamp set to sync.

• Add parseEventsWithClipboard() to keyEventDisplayService.js
• Update player.js handlers to merge key and clipboard events

This PR goes in hand with https://github.com/apache/guacamole-server/pull/530