[HTML] Made HTML layout more uniform and optimize CSS

- Replaced all <TH> with functions
- Optimized CSS (removed some errors too)
- Uniform rendering of pages (TH, width first column)
- Added some metadata to timing stats page
- Reduction in used flash strings.

src/ESPEasy-Globals.h

@@ -1899,6 +1899,7 @@ unsigned long timingstats_last_reset = 0;
 #define HOST_BY_NAME_STATS   29
 #define CONNECT_CLIENT_STATS 30
 #define LOAD_CUSTOM_TASK_STATS 31
+#define WIFI_ISCONNECTED_STATS 32
 
 
 
@@ -1930,6 +1931,7 @@ String getMiscStatsName(int stat) {
         case HOST_BY_NAME_STATS:    return F("hostByName()");
         case CONNECT_CLIENT_STATS:  return F("connectClient()");
         case LOAD_CUSTOM_TASK_STATS: return F("LoadCustomTaskSettings()");
+        case WIFI_ISCONNECTED_STATS: return F("WiFi.isConnected()");
         case C001_DELAY_QUEUE:
         case C002_DELAY_QUEUE:
         case C003_DELAY_QUEUE:

src/ESPEasyWifi.ino

@@ -459,9 +459,13 @@ bool useStaticIP() {
 }
 
 bool WiFiConnected() {
+  START_TIMER;
   // For ESP82xx, do not rely on WiFi.status() with event based wifi.
   if (wifiStatus == ESPEASY_WIFI_SERVICES_INITIALIZED) {
-    if (WiFi.isConnected()) return true;
+    if (WiFi.isConnected()) {
+      STOP_TIMER(WIFI_ISCONNECTED_STATS);
+      return true;
+    }
     // else wifiStatus is no longer in sync.
     resetWiFi();
   }