dnspython: Add compatibility shim

`dnspython` 2.0.0 has many changes and several deprecations like:

```
> dns.resolver.resolve() has been added, allowing control of whether
search lists are used. dns.resolver.query() is retained for backwards
compatibility, but deprecated. The default for search list behavior can
be set at in the resolver object with the use_search_by_default
parameter. The default is False.

> dns.resolver.resolve_address() has been added, allowing easy
address-to-name lookups.
```

The new class `DNSResolver`:
- provides the compatibility layer
- defaults the previous behavior (the search list configured in the
  system's resolver configuration is used for relative names)
- defaults lifetime to 15sec (determines the number of seconds
  to spend trying to get an answer to the question)

Fixes: https://pagure.io/freeipa/issue/8383
Signed-off-by: Stanislav Levin <slev@altlinux.org>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>

ipaserver/install/server/replicainstall.py

@@ -9,8 +9,6 @@ import logging
 
 import dns.exception as dnsexception
 import dns.name as dnsname
-import dns.resolver as dnsresolver
-import dns.reversename as dnsreversename
 import os
 import shutil
 import socket
@@ -28,6 +26,7 @@ from ipalib.install import certstore, sysrestore
 from ipalib.install.kinit import kinit_keytab
 from ipapython import ipaldap, ipautil
 from ipapython.dn import DN
+from ipapython.dnsutil import DNSResolver
 from ipapython.admintool import ScriptError
 from ipapython.ipachangeconf import IPAChangeConf
 from ipaplatform import services
@@ -289,7 +288,7 @@ def check_dns_resolution(host_name, dns_servers):
         logger.error(
             'Could not resolve any DNS server hostname: %s', dns_servers)
         return False
-    resolver = dnsresolver.Resolver()
+    resolver = DNSResolver()
     resolver.nameservers = server_ips
 
     logger.debug('Search DNS server %s (%s) for %s',
@@ -299,7 +298,7 @@ def check_dns_resolution(host_name, dns_servers):
     addresses = set()
     for rtype in 'A', 'AAAA':
         try:
-            result = resolver.query(host_name, rtype)
+            result = resolver.resolve(host_name, rtype)
         except dnsexception.DNSException:
             rrset = []
         else:
@@ -327,8 +326,7 @@ def check_dns_resolution(host_name, dns_servers):
         checked.add(address)
         try:
             logger.debug('Check reverse address %s (%s)', address, host_name)
-            revname = dnsreversename.from_address(address)
-            rrset = resolver.query(revname, 'PTR').rrset
+            rrset = resolver.resolve_address(address).rrset
         except Exception as e:
             logger.debug('Check failed: %s %s', type(e).__name__, e)
             logger.error(