Implement Improv via Serial component (#2423)

Co-authored-by: Paulus Schoutsen <balloob@gmail.com>

esphome/components/wifi/__init__.py

@@ -140,7 +140,8 @@ def final_validate(config):
     has_sta = bool(config.get(CONF_NETWORKS, True))
     has_ap = CONF_AP in config
     has_improv = "esp32_improv" in fv.full_config.get()
-    if (not has_sta) and (not has_ap) and (not has_improv):
+    has_improv_serial = "improv_serial" in fv.full_config.get()
+    if not (has_sta or has_ap or has_improv or has_improv_serial):
         raise cv.Invalid(
             "Please specify at least an SSID or an Access Point to create."
         )

esphome/components/wifi/wifi_component.cpp

@@ -239,8 +239,6 @@ void WiFiComponent::save_wifi_sta(const std::string &ssid, const std::string &pa
   sta.set_ssid(ssid);
   sta.set_password(password);
   this->set_sta(sta);
-
-  this->start_scanning();
 }
 
 void WiFiComponent::start_connecting(const WiFiAP &ap, bool two) {