feat: add colored and formatted logging

Add a custom logging setup function to add custom levels and custom
formatters (partly for future use with extended logging functionality).
Also implemented a basic colored formatter to make our logs nicer.

Also improved the handling of logging in external libraries, so now we
should only get WARNings or above.

ref: N25B-233

logging_config.yaml

@@ -0,0 +1,41 @@
+version: 1
+
+custom_levels:
+  OBSERVATION: 25
+  ACTION: 26
+
+formatters:
+  # Console output
+  colored:
+    (): 'colorlog.ColoredFormatter'
+    format: '{log_color}{asctime} | {levelname:11} | {name:70} | {message}'
+    style: '{'
+    datefmt: '%H:%M:%S'
+
+  # User-facing UI (structured JSON)
+  json_experiment:
+    (): 'pythonjsonlogger.jsonlogger.JsonFormatter'
+    format: '{asctime} {name} {levelname} {message}'
+    style: '{'
+
+
+handlers:
+  console:
+    class: logging.StreamHandler
+    level: DEBUG
+    formatter: colored
+    stream: ext://sys.stdout
+
+# Level of external libraries
+root:
+  level: WARN
+  handlers: [console]
+
+loggers:
+  experiment:
+    level: OBSERVATION
+    handlers: [console]  # TODO: custom handler for user-facing logs (ticket about UI logs)
+    propagate: no
+  control_backend:
+    level: INFO
+