Improve styling of xpage folders and documents

cdekort suggests in CMS-14317 to improve the styling of the icons for xpage folders and documents in the content perspective. See https://issues.onehippo.com/browse/CMS-14317?focusedCommentId=595396&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-595396.

The starred folder icon in the tree seems smaller than the other folder icons. We want to change several icons to follow Material.

Icon assets link: https://drive.google.com/open?id=1yKXsbj0O67tHY6aZQuLCMTfo8VTXxKAD&authuser=nien-hua.gu%40bloomreach.com&usp=drive_fs

Invision design mockup: https://bloomreach.invisionapp.com/console/share/UP2BCG5S98/570090607

Acceptance criteria

Black in 60% (except status icons)

• 10px - to be switched
  • Chevrons  right
  • Chevron down
• 16px - to be added / switched
  • Folder opened
  • Folder closed (small and large)
  • X-page folder opened
  • X-page folder closed (small and large)
• 16px status - to be switched
  • Status published
  • Status modified
  • Status offline
• 32px - to be switched

• • Folder
  • Page folder
  • Doc
  • Page
  • Document type
  • Compound fields
• 36px - to be switched in Project
  • Page
  • Doc