Subsite reports link to main site

Problem/Motivation

Installed the module on a multisite main/subsite installation. Can't use it properly in the subsites.

• When I examine the report in a subsite, the paragraphs Path links are absolute to the main site.
• The button for Update Report Data links to the main site.
• Inspecting the Filter by Type form element on admin/reports/paragraphs-report, the action is an absolute reference to the root of the site:
  <form method="get" action="/admin/reports/paragraphs-report">

Steps to reproduce

In the report on a subsite:

• Click on the path of any paragraph in the report which typically results in a 404 since the paragraph is used in the subsite and not the main site.
• Click on the Update Report Data button. It will go to /admin/reports/paragraphs-report/update in the main site.
• Use the Filter by Type form, it will post the form to the report in the main site and filter to the chosen paragraph type.

Proposed resolution

Fix paths to account for use in subsites.

Remaining tasks

User interface changes

API changes

Data model changes