refactor: use StringBuilder in SearchUriBuilder

for better readability and potentially improved performance

Author: gurza

src/CompaniesHouse/UriBuilders/SearchCompanyUriBuilder.cs

@@ -1,4 +1,5 @@
-using CompaniesHouse.Request;
+using System.Text;
+using CompaniesHouse.Request;
 
 namespace CompaniesHouse.UriBuilders;
 
@@ -10,13 +11,13 @@ public SearchCompanyUriBuilder(string path) : base(path)
 
     protected override string BuildQuery(SearchCompanyRequest request)
     {
-        var query = base.BuildQuery(request);
+        var queryBuilder = new StringBuilder(base.BuildQuery(request));
 
         if (!string.IsNullOrWhiteSpace(request.Restrictions))
         {
-            query += "&restrictions=" + request.Restrictions;
+            queryBuilder.Append($"&restrictions={Uri.EscapeDataString(request.Restrictions)}");
         }
 
-        return query;
+        return queryBuilder.ToString();
     }
 }

src/CompaniesHouse/UriBuilders/SearchUriBuilder.cs

@@ -1,4 +1,4 @@
-using System;
+using System.Text;
 using CompaniesHouse.Request;
 
 namespace CompaniesHouse.UriBuilders
@@ -23,19 +23,19 @@ public Uri Build(TSearch request)
 
         protected virtual string BuildQuery(TSearch request)
         {
-            var query = $"?q={Uri.EscapeDataString(request.Query)}";
+            var queryBuilder = new StringBuilder($"?q={Uri.EscapeDataString(request.Query)}");
 
             if (request.ItemsPerPage.HasValue)
             {
-                query += "&items_per_page=" + request.ItemsPerPage.Value;
+                queryBuilder.Append($"&items_per_page={request.ItemsPerPage.Value}");
             }
 
             if (request.StartIndex.HasValue)
             {
-                query += "&start_index=" + request.StartIndex.Value;
+                queryBuilder.Append($"&start_index={request.StartIndex.Value}");
             }
 
-            return query;
+            return queryBuilder.ToString();
         }
     }
 }