View test results gathered by Tags

I'm submitting a ...

[X ] feature request

What is the current behavior?

Currently, I m not able to display the test result summary gathered by tests tags, like in the Robot Framework report :

What is the expected behavior?

I would like to be able to display a summary of the test result gathered by tests tags.

Allure version: 2.12.1
Test framework: robotframework@3.0.2
Allure adaptor: allure-robotframework@2.8.6

Start by reviewing how Allure Report displays test results and how allure-robotframework@2.8.6 supplies test tags. Confirm the desired grouping and summary metrics from the Robot Framework example; the work is done when the report displays test-result summaries grouped by tags.

Written by the indexing model from the issue text.