[🔧 site]: create "cumulative" page to use in performance tests

[ala-n]

As an ESL marketing activities member, I want to have a page to use in performance showcases.

Page requirements:

• >80% ESL components were used
• page should be realistic enough
• page will be used for lighthouse tests
• assets used on the page should be optimized

[ala-n]

Postponed under site redesign topic