Accessibility fixes for confluence-editor bundled plugin

Problem Definition

Currently there are a few accessibility issues with the templates for this plugin, for example it is missing some accessibility code:

• page-editor-permissions.js (and page-editor-permissions-min.js)
  add aria-label to restriction button
• page-editor-quit-dialog.js (and page-editor-quit-dialog-min.js)
  add role="dialog", assistive text and aria-label to qed-discard-button
  remove title attribute from qed-discard-button and qed-publish-button (not required because text inside is the same as title)
• page-editor-ui.js (and page-editor-ui-min.js)
  add aria-label to rte-button-labels
• page-editor.soy
  update tabindex to 0 (101 is not a valid tab index)