[logger] Add runtime level select (#8222)

Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>

tests/components/logger/common-default_uart.yaml

@@ -1,7 +1,17 @@
 esphome:
   on_boot:
     then:
-      - logger.log: Hello world
+      - logger.log:
+          level: warn
+          format: "Warning: Logger level is %d"
+          args: [id(logger_id).get_log_level()]
+      - logger.set_level: WARN
 
 logger:
+  id: logger_id
   level: DEBUG
+  initial_level: INFO
+
+select:
+  - platform: logger
+    name: Logger Level