add Http.SendAsync, refactor PluginsManifest to use it

Author: JohnTheGr8

Flow.Launcher.Core/ExternalPlugins/PluginsManifest.cs

@@ -1,3 +1,4 @@
+using Flow.Launcher.Infrastructure.Http;
 using Flow.Launcher.Infrastructure.Logger;
 using System;
 using System.Collections.Generic;
@@ -13,8 +14,6 @@ public static class PluginsManifest
     {
         private const string manifestFileUrl = "https://cdn.jsdelivr.net/gh/Flow-Launcher/Flow.Launcher.PluginsManifest@plugin_api_v2/plugins.json";
 
-        private static HttpClient httpClient = new HttpClient();
-
         private static readonly SemaphoreSlim manifestUpdateLock = new(1);
 
         private static string latestEtag = "";
@@ -30,7 +29,7 @@ public static async Task UpdateManifestAsync(CancellationToken token = default)
                 var request = new HttpRequestMessage(HttpMethod.Get, manifestFileUrl);
                 request.Headers.Add("If-None-Match", latestEtag);
 
-                var response = await httpClient.SendAsync(request, token).ConfigureAwait(false);
+                var response = await Http.SendAsync(request, token).ConfigureAwait(false);
 
                 if (response.StatusCode == HttpStatusCode.OK)
                 {

Flow.Launcher.Infrastructure/Http/Http.cs

@@ -153,5 +153,13 @@ public static async Task<Stream> GetStreamAsync([NotNull] string url, Cancellati
             var response = await client.GetAsync(url, HttpCompletionOption.ResponseHeadersRead, token);
             return await response.Content.ReadAsStreamAsync();
         }
+
+        /// <summary>
+        /// Asynchrously send an HTTP request.
+        /// </summary>
+        public static async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken token = default)
+        {
+            return await client.SendAsync(request, token);
+        }
     }
 }