Add suplementary rake tasks for distributed hll

What does this MR do?

It aim to provide supplementary rake tasks to conduct robust HyperLogLog implementation accuracy analysis

Proposed rake tasks uses statistical methods that assess accuracy of algorithm implementation over big set of algorithm estimation, instead of single run that is pron to be skewed by probabilistic nature of algorithm.

In original paper http://algo.inria.fr/flajolet/Publications/FlFuGaMe07.pdf mathematical method used to asses accuracy was relative standard error

Implements: #299184 (closed)

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team