[6.15.z] Rely on dynaconf to render the config based on is_ipv6 setting

[Satellite-QE]

Cherrypick of PR: #16886

Problem Statement

The REPOS section of the config contains -ipv4 hostnames despite the is_ipv6 setting being set to True. This happens because we are looping through the non-templatized/non-formatted configuration loaded by the dynaconf YAML loader:

robottelo/robottelo/utils/url.py

Line 46 in a79da44

all_settings = settings.loaded_by_loaders.items()

Since the REPOS config section contains several templates, either @format or @jinja, injecting a string containing -ipv4, and since our algorithm uses the raw config file value loaded by the YAML loader, we are not able to detect this case and change these URLs and hostnames to -ipv6.

Solution

The proposed solution is to shift to a different approach - from mutating settings by an algorithm in robottelo to creating a self-contained configuration structure and including IPv4 and IPv6 URLs and hostnames in the config. Based on the IS_IPV6 setting, templatize the value of the actual hostname/URL config field.

Related Issues

https://issues.redhat.com/browse/SAT-29304
satellite-jenkins!1545