Pull request: home: mv local domain name to dhcp setts

Closes #3367.

Squashed commit of the following:

commit e2cabcac2d91af24b9e5f4ac8f78daf5e8d339b9
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Jan 25 19:35:31 2022 +0300

    home: imp test, skip dhcp test on windows

commit e58053f11e081630ad4e8d1e77a7a74226029db0
Merge: ff2fe87d 0b72bcc5
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Jan 25 19:10:25 2022 +0300

    Merge branch 'master' into 3367-dhcp-local-domain-name

commit ff2fe87d8cab12e60d045be636e366e392d6d96f
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Dec 30 20:55:34 2021 +0300

    home: mv local domain name to dhcp setts

CHANGELOG.md

@@ -21,9 +21,33 @@ and this project adheres to
 
 ### Changed
 
+- The setting `local_domain_name` is now in the `dhcp` block in the
+  configuration file to avoid confusion ([#3367]).
 - The `dns.bogus_nxdomain` configuration file parameter now supports CIDR
   notation alongside IP addresses ([#1730]).
 
+#### Configuration Changes
+
+In this release, the schema version has changed from 12 to 13.
+
+- Parameter `local_domain_name`, which in schema versions 12 and earlier used to
+  be a part of the `dns` object, is now a part of the `dhcp` object:
+
+  ```yaml
+  # BEFORE:
+  'dns':
+    # …
+    'local_domain_name': 'lan'
+
+  # AFTER:
+  'dhcp':
+    # …
+    'local_domain_name': 'lan'
+  ```
+
+  To rollback this change, move the parameter back into `dns` and change the
+  `schema_version` back to `12`.
+
 ### Deprecated
 
 <!--
@@ -38,6 +62,7 @@ and this project adheres to
 
 [#1730]: https://github.com/AdguardTeam/AdGuardHome/issues/1730
 [#3057]: https://github.com/AdguardTeam/AdGuardHome/issues/3057
+[#3367]: https://github.com/AdguardTeam/AdGuardHome/issues/3367