Admin page permissions too generic

Problem/Motivation

I'd like my client to be able to upload / update the H5P Libaries without having the very bulky "administer site configuration" permission.

Steps to reproduce

Install the module and try to access /admin/content/h5p with a user that does not have the "administer site configuration" permission.

Proposed resolution

Add a new permission that can be assigned without giving the user access to global site configuration.

Remaining tasks

Define Permission and change route permission checks.

User interface changes

Newly added permission.

API changes

None.

Data model changes

None.