Make Google Analytics generation configurable (as in Allure 2)

In Allure 3, Google Analytics generation is no longer configurable, unlike in Allure 2 where it could be explicitly disabled via [environment variable.](https://github.com/allure-framework/allure2/blob/main/Analytics.md?plain=1#L27)
Please add a configuration option to control or disable Google Analytics generation.

Locate the current Google Analytics generation entry point in Allure 3 and compare its behavior with the Allure 2 Analytics.md reference linked in the issue. Add a configuration option that controls or disables generation, and verify that both enabled and disabled behavior work as intended.

Written by the indexing model from the issue text.