Test NP logging config reload on SIGHUP (#57681) (#58107)

* TSify reload config test and simplify logic

* get rid of mutable config in tests

* increase timeouts

* address comments

src/cli/serve/integration_tests/__fixtures__/reload_logging_config/kibana.test.yml

@@ -1,8 +1,11 @@
 server:
+  autoListen: false
   port: 8274
 logging:
   json: true
 optimize:
   enabled: false
 plugins:
   initialize: false
+migrations:
+  skip: true

src/cli/serve/integration_tests/__fixtures__/reload_logging_config/kibana_log_console.test.yml

@@ -0,0 +1,22 @@
+server:
+  autoListen: false
+  port: 8274
+logging:
+  loggers:
+    - context: root
+      appenders:
+        - console
+      level: debug
+  appenders:
+    console:
+      kind: console
+      layout:
+        kind: json
+  root:
+    level: debug
+optimize:
+  enabled: false
+plugins:
+  initialize: false
+migrations:
+  skip: true

src/cli/serve/integration_tests/__fixtures__/reload_logging_config/kibana_log_file.test.yml

@@ -0,0 +1,22 @@
+server:
+  autoListen: false
+  port: 8274
+logging:
+  loggers:
+    - context: root
+      appenders:
+        - file
+      level: debug
+  appenders:
+    file:
+      kind: file
+      layout:
+        kind: pattern
+  root:
+    level: debug
+optimize:
+  enabled: false
+plugins:
+  initialize: false
+migrations:
+  skip: true