Human readable Uptime (#986)

* Human readable Uptime

* Uptime from Frenck code

* Uptime with Frenck code

* Updated Human Readable Uptime

* Removed trailing spaces

* Renamed sensor to "Last started"

Sensor renamed
Update moved to the boot process
Clean-up

---------

Co-authored-by: Edward Firmo <94725493+edwardtfn@users.noreply.github.com>
Co-authored-by: Edward Firmo <edward@costafirmo.com>

nspanel_esphome.yaml

@@ -823,10 +823,15 @@ binary_sensor:
 ##### START - SENSOR CONFIGURATION #####
 sensor:
 
-  ##### Uptime #####
-  - name: ${device_name} uptime
-    platform: uptime
-    disabled_by_default: true
+  ##### Uptime Template #####
+  - name: ${device_name} Last started
+    id: last_started
+    platform: template
+    internal: false
+    device_class: timestamp
+    entity_category: diagnostic
+    accuracy_decimals: 0
+    update_interval: never
 
   ##### WIFI Signal stregth
   - name: ${device_name} RSSI
@@ -1311,6 +1316,9 @@ display:
         - lambda: id(disp1).set_component_text_printf("boot.esph_version", "%s", "${version}"); ### esphome-version ###
         - wait_until:
             api.connected
+        - sensor.template.publish:
+            id: last_started
+            state: !lambda 'return id(time_provider).utcnow().timestamp;'
         - lambda: id(disp1).set_component_text_printf("boot.ip_addr", "%s", id(ip_address).state.c_str());
         - delay: 1s
         - number.set: