Describe the bug
When configuring "Page Rules" the administration allow to limit access by "Tags" (which is, by far, the most intuitive and fast way to configure access rights).

However these limits won't work correctly on assets added to pages.

To Reproduce
Steps to reproduce the behavior:

1. Access Administration
2. Create a User Group
3. Add a simple page rule based on Tag matches
4. Create a User and assign it to the User Group
5. Create a Page and use the correct tag
6. Add an asset to the page
7. Access the page with the created user. Page should be accessible while the asset shouldn't

Expected behavior
Assets should have tags too or being able to inherit them from pages on which are inserted

Screenshots

As shown in the previou screenshot, to limit access to the assets I had to:

• build a specific tree structure on which upload the assets
• add more rules, based on paths, to allow the correct access rights to the assets

Host Info:

• OS: Linux, Debian 10, Docker
• Wiki.js version: 2.4.107
• Database engine: postgres 9.7

Additional context
Add any other context about the problem here.