feat: create libretime_shared package (#1349)

* feat: create libretime_shared package

- We don't use pydantic.BaseSettings because of some
  incompatble loading behavior.

* fix: whitelist pydantic in pylintrc

* docs: update to new BaseConfig behavior

* docs: change confusing config filepath

shared/libretime_shared/cli.py

@@ -0,0 +1,65 @@
+from typing import Callable
+
+import click
+
+from .config import DEFAULT_ENV_PREFIX
+
+
+def cli_logging_options(func: Callable) -> Callable:
+    """
+    Decorator function to add logging options to a click application.
+
+    This decorator add the following arguments:
+    - verbosity: int
+    - log_filepath: Path
+    """
+    func = click.option(
+        "-v",
+        "--verbose",
+        "verbosity",
+        envvar=f"{DEFAULT_ENV_PREFIX}_VERBOSITY",
+        count=True,
+        default=0,
+        help="Increase logging verbosity (use -vvv to debug).",
+    )(func)
+
+    func = click.option(
+        "-q",
+        "--quiet",
+        "verbosity",
+        is_flag=True,
+        flag_value=-1,
+        help="Decrease logging verbosity.",
+    )(func)
+
+    func = click.option(
+        "--log-filepath",
+        "log_filepath",
+        envvar=f"{DEFAULT_ENV_PREFIX}_LOG_FILEPATH",
+        type=click.Path(),
+        help="Path to the logging file.",
+        default=None,
+    )(func)
+
+    return func
+
+
+def cli_config_options(func: Callable) -> Callable:
+    """
+    Decorator function to add config file options to a click application.
+
+    This decorator add the following arguments:
+    - config_filepath: Path
+    """
+
+    func = click.option(
+        "--c",
+        "--config",
+        "config_filepath",
+        envvar=f"{DEFAULT_ENV_PREFIX}_CONFIG_FILEPATH",
+        type=click.Path(),
+        help="Path to the config file.",
+        default=None,
+    )(func)
+
+    return func