refactor(MikrotikTools): improve server search input layout and styling for better usability

frontend/src/MikrotikTools.jsx

@@ -224,18 +224,22 @@ function MikrotikTools() {
                   : 'Выберите сервер, чтобы выполнять проверки через него.'}
               </div>
             </div>
-            <div className="col-auto" style={{ minWidth: 260 }}>
-              <div className="input-group input-group-flat">
-                <input
-                  type="text"
-                  className="form-control"
-                  placeholder="Поиск серверов по IP, DNS, провайдеру..."
-                  value={serverSearch}
-                  onChange={(e) => setServerSearch(e.target.value)}
-                />
-                <span className="input-group-text">
-                  <IconSearch size={16} className="text-muted" />
-                </span>
+            <div className="col-auto ms-auto d-print-none" style={{ minWidth: 260 }}>
+              <div className="d-flex">
+                <div className="me-0 flex-grow-1">
+                  <div className="input-icon">
+                    <input
+                      type="text"
+                      className="form-control form-control-sm"
+                      placeholder="Поиск серверов..."
+                      value={serverSearch}
+                      onChange={(e) => setServerSearch(e.target.value)}
+                    />
+                    <span className="input-icon-addon">
+                      <IconSearch size={16} className="text-muted" />
+                    </span>
+                  </div>
+                </div>
               </div>
             </div>
           </div>