Add app identifier to User-Agent for Nominatim requests

An openstreetmap.org system administrator recommended we include an app
identifier in the User-Agent header. My inference is that they block
based on the User-Agent. However, I did not want to use only the app
identifier so I found the form that Craft uses and copied that,
appending the app identifier.

Author: Brandon Plubell

src/services/GeoService.php

@@ -21,6 +21,7 @@
 use GuzzleHttp\Client;
 use Mapkit\JWT;
 use Exception;
+use function GuzzleHttp\default_user_agent;
 
 /**
  * Class GeoService
@@ -763,13 +764,9 @@ private static function _latLngFromAddress_Mapbox ($token, $address, $country):
 				$url = str_replace('.json', rawurlencode(', ' . $country) . '.json', $url);
 		}
 
-		$referer = Craft::$app->getRequest()->getIsConsoleRequest()
-			? Craft::getAlias('@web')
-			: Craft::$app->urlManager->getHostInfo();
-
 		$data = (string) static::_client()->get($url, [
             'headers' => [
-                'referer' => $referer,
+                'referer' => static::_referer(),
             ]
         ])->getBody();
 		$data = Json::decodeIfJson($data);
@@ -796,13 +793,10 @@ private static function _latLngFromAddress_Nominatim ($address, $country): ?arra
 				$url .= '&country=' . rawurlencode($country);
 		}
 
-		$referer = Craft::$app->getRequest()->getIsConsoleRequest()
-			? Craft::getAlias('@web')
-			: Craft::$app->urlManager->getHostInfo();
-
 		$data = (string) static::_client()->get($url, [
 			'headers' => [
-				'referer' => $referer
+				'referer' => static::_referer(),
+				'user-agent' => static::_userAgent(),
 			]
 		])->getBody();
 		$data = Json::decodeIfJson($data);
@@ -891,13 +885,10 @@ private static function _addressFromLatLng_Nominatim ($lat, $lng): ?array
 		$url .= '&accept-language=' . Craft::$app->locale->getLanguageID();
 		$url .= '&lat=' . rawurlencode($lat) . '&lon=' . rawurldecode($lng);
 
-		$referer = Craft::$app->getRequest()->getIsConsoleRequest()
-			? Craft::getAlias('@web')
-			: Craft::$app->urlManager->getHostInfo();
-
 		$data = (string) static::_client()->get($url, [
 			'headers' => [
-				'referer' => $referer
+				'referer' => static::_referer(),
+				'user-agent' => static::_userAgent(),
 			]
 		])->getBody();
 		$data = Json::decodeIfJson($data);
@@ -930,6 +921,21 @@ private static function _client ()
 		return $client;
 	}
 
+	private static function _referer ()
+	{
+		return Craft::$app->getRequest()->getIsConsoleRequest()
+			? Craft::getAlias('@web')
+			: Craft::$app->urlManager->getHostInfo();
+	}
+
+	private static function _userAgent ()
+	{
+		// User agent form based on Craft::createGuzzleClient
+		return 'Craft/' . Craft::$app->getVersion()
+			. ' ' . default_user_agent()
+			. ' ' . static::_referer();
+	}
+
 	private static function _validateCountryCode (string $code): bool
 	{
 		return in_array(strtoupper($code), array_keys(static::$countries));