[update] Implement `update.perform action and update.is_available` condition (#7165)

* [update] Fix unimplemented yaml action/condition

* Add/update tests

---------

Co-authored-by: Keith Burzinski <kbx81x@gmail.com>

tests/components/update/common.yaml

@@ -1 +1,28 @@
+substitutions:
+  verify_ssl: "true"
+
+esphome:
+  on_boot:
+    then:
+      - if:
+          condition:
+            update.is_available:
+          then:
+            - logger.log: "Update available"
+      - update.perform:
+          force_update: true
+
+wifi:
+  ssid: MySSID
+  password: password1
+
+http_request:
+  verify_ssl: ${verify_ssl}
+
+ota:
+  - platform: http_request
+
 update:
+  - platform: http_request
+    name: Firmware Update
+    source: http://example.com/manifest.json