Pull request: 4698 Gateway IP in DHCP Lease

Closes #4698.

Squashed commit of the following:

commit 6be0caee58926f8cea1e10650fbde0c8d97d0dac
Author: Ildar Kamalov <ik@adguard.com>
Date:   Fri Jul 8 13:41:50 2022 +0300

    update translation

commit e0370656d05e8463d73ea73568cae81187c6b2e3
Author: Ildar Kamalov <ik@adguard.com>
Date:   Fri Jul 8 13:40:54 2022 +0300

    client: validate static lease ip

commit 7f4d00f9f3a54dc93ce5d5c45e9c21745f6e39d1
Merge: 2ee79626 77e5e27d
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Fri Jul 8 13:20:15 2022 +0300

    Merge branch 'master' into 4698-lease-with-gateway

commit 2ee79626a1b0c7b113dbd22ba4ef6e85ea9913ec
Merge: 471b96b8 3505ce87
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Jul 7 19:34:33 2022 +0300

    Merge branch 'master' into 4698-lease-with-gateway

commit 471b96b81da8920c1e71b7110050154f912677d2
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Jul 7 16:07:23 2022 +0300

    dhcpd: imp docs

commit 67dd6c76f7d2df4712a57281e0f40f2ee1a1efa2
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Jul 7 15:48:47 2022 +0300

    dhcpd: restrict gateway ip for lease

client/src/components/Settings/Dhcp/StaticLeases/Form.js

@@ -10,6 +10,7 @@ import {
     validateMac,
     validateRequiredValue,
     validateIpv4InCidr,
+    validateIpGateway,
 } from '../../../../helpers/validators';
 import { FORM_NAME } from '../../../../helpers/constants';
 import { toggleLeaseModal } from '../../../../actions';
@@ -57,6 +58,7 @@ const Form = ({
                             validateRequiredValue,
                             validateIpv4,
                             validateIpv4InCidr,
+                            validateIpGateway,
                         ]}
                     />
                 </div>
@@ -101,6 +103,7 @@ Form.propTypes = {
         ip: PropTypes.string.isRequired,
         hostname: PropTypes.string.isRequired,
         cidr: PropTypes.string.isRequired,
+        gatewayIp: PropTypes.string,
     }),
     pristine: PropTypes.bool.isRequired,
     handleSubmit: PropTypes.func.isRequired,

client/src/components/Settings/Dhcp/StaticLeases/Modal.js

@@ -13,6 +13,7 @@ const Modal = ({
     cidr,
     rangeStart,
     rangeEnd,
+    gatewayIp,
 }) => {
     const dispatch = useDispatch();
 
@@ -42,6 +43,7 @@ const Modal = ({
                         cidr,
                         rangeStart,
                         rangeEnd,
+                        gatewayIp,
                     }}
                     onSubmit={handleSubmit}
                     processingAdding={processingAdding}
@@ -61,6 +63,7 @@ Modal.propTypes = {
     cidr: PropTypes.string.isRequired,
     rangeStart: PropTypes.string,
     rangeEnd: PropTypes.string,
+    gatewayIp: PropTypes.string,
 };
 
 export default withTranslation()(Modal);

client/src/components/Settings/Dhcp/StaticLeases/index.js

@@ -24,6 +24,7 @@ const StaticLeases = ({
     cidr,
     rangeStart,
     rangeEnd,
+    gatewayIp,
 }) => {
     const [t] = useTranslation();
     const dispatch = useDispatch();
@@ -106,6 +107,7 @@ const StaticLeases = ({
                 cidr={cidr}
                 rangeStart={rangeStart}
                 rangeEnd={rangeEnd}
+                gatewayIp={gatewayIp}
             />
         </>
     );
@@ -119,6 +121,7 @@ StaticLeases.propTypes = {
     cidr: PropTypes.string.isRequired,
     rangeStart: PropTypes.string,
     rangeEnd: PropTypes.string,
+    gatewayIp: PropTypes.string,
 };
 
 cellWrap.propTypes = {

client/src/components/Settings/Dhcp/index.js

@@ -278,6 +278,7 @@ const Dhcp = () => {
                             cidr={cidr}
                             rangeStart={dhcp?.values?.v4?.range_start}
                             rangeEnd={dhcp?.values?.v4?.range_end}
+                            gatewayIp={dhcp?.values?.v4?.gateway_ip}
                         />
                         <div className="btn-list mt-2">
                             <button