Modernize the report.html when using the --modern-ui Flag

[andrewbaldwin44]

Prerequisites

• I am using the latest version of Locust
• I am suggesting a new feature, not asking a question

Description

Is your feature request related to a problem? Please describe.

Following suite with the new modern web UI #2396, we should modernize the report.html as well

Describe the solution you'd like

When the --modern-ui flag is active, return a modern looking report.html using the same technologies as the new modern ui. When the flag is not active, the report.html should be unchanged

Additional context

Already have a PR ready for this!

[cyberw]

Fixed in #2420