Implementes retries on failed requests

[joente]

Description

In the real world, a website might not respond, just for a millisecond and we have to decide if we want to retry in such a case.
This also adds the retries (int) metric which indicates the number of retries used. (Should be 0 if the website could be reached, a value >0 means at least one retry was used to access the website.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

• Test using alpha version

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• New and existing unit tests pass locally with my changes