Feature: Add ability to control the name of the section used in the SSSD config file
for the domain/realm specific settings, as managed by `ad_dyndns_update` and
`ad_integration_sssd_custom_settings`. By default, the role will use the lower
case of the `ad_integration_realm`, but in some cases you want to use the actual
case of `ad_integration_realm`. There is a new option
`ad_integration_sssd_realm_preserve_case` which can be set to `true` to preserve
the case of the realm. This may leave the SSSD config file with multiple sections
for the realm. Use the new `ad_integration_sssd_remove_duplicate_sections` setting
to consolidate all of the settings from the multiple sections into the chosen
section.

Reason: The SSSD config file is not "owned" by the ad_integration role and must
be able to use the realm/domain section as configured.

Result: The ad_integration role can manage domain/realm sections in the SSSD
config file correctly.

Signed-off-by: Rich Megginson <rmeggins@redhat.com>

1. 1. Summary by Sourcery

Enable control over SSSD domain section naming and duplicate consolidation, fix handling of uppercase domains, refactor task logic, and update documentation, defaults, and tests accordingly

New Features:

• Allow preserving the case of the AD realm in the SSSD domain section via ad_integration_sssd_realm_preserve_case
• Add ad_integration_sssd_remove_duplicate_sections to merge and remove duplicate domain sections in sssd.conf

Bug Fixes:

• Fix incorrect SSSD configuration when using non-lowercase domain names

Enhancements:

• Refactor SSSD settings task to load existing sssd.conf, detect and consolidate matching domain sections case-insensitively
• Unify configuration of sssd, dynamic DNS, and custom settings under a single block with computed section logic

Documentation:

• Update README to explain realm casing and duplicate section removal options

Tests:

• Update tests to use dynamic __ad_integration_sssd_conf path, expose role tests as public, and add migration scenarios for duplicate section handling