nspanel: popups for OTA progress and device info, Info card on every panel

common/nspanel_popup.yaml shows a popupNotify page during OTA (written straight
to the display uart, since OTA blocks the loop that sends the component's
queued commands) and a device info popup (version, build time, IPs) from the
Info button on the new last card or the show_info API action. The OTA gets
id ota_esphome to extend it. Also documents the NSPanel pinout.

mcu-nspanel-bedroom.yaml

@@ -1,4 +1,18 @@
 ---
+# Hardware: Sonoff NSPanel (EU)
+# Pinout:
+#   GPIO2   IO2
+#   GPIO4   Screen power                  -> Screen Power (switch gpio) (inverted)
+#   GPIO14  Left button                   -> Left Button (binary_sensor gpio) (inverted)
+#   GPIO16  Display UART TX               -> display_uart (uart tx_pin)
+#   GPIO17  Display UART RX               -> display_uart (uart rx_pin)
+#   GPIO19  Relay 2
+#   GPIO21  Buzzer                        -> buzzer_out (output ledc)
+#   GPIO22  Relay 1                       -> relay_1 (output gpio)
+#   GPIO23  Relay 3 (no relay, connector)
+#   GPIO27  Right button                  -> Right Button (binary_sensor gpio) (inverted)
+#   GPIO37  ALS (light sensor)
+#   GPIO38  NTC temperature (ADC)         -> ntc_source (sensor adc)
 substitutions:
   device: nspanel-bedroom
   name: Bedroom NSPanel
@@ -51,6 +65,13 @@ nspanel_lovelace:
       title: Kúrenie
       thermo_entity_id: climate.bt_trv_bedroom
 
+    - type: cardEntities
+      title: Info
+      entities:
+        - name: Zariadenie
+          entity_id: button.bedroom_nspanel_info
+          icon: information-outline
+
 binary_sensor:
   - platform: gpio
     name: Left Button