Adds debug console cli command

Why are these changes being introduced:

* tim_os will never have all of the features of the opensearch client
  library
* accessing opensearch in aws is a pain due to the v4 signing without
  using a client

How does this address that need:

* Create a CLI option that drops you into a debugger with a client
  preconfigured for your connection

Document any side effects to this change:

* this loads the pdb debugger into production code which is not ideal

tim/cli.py

@@ -352,3 +352,20 @@ def bulk_delete(
         results["deleted"],
         results["total"],
     )
+
+
+@main.command()
+@click.pass_context
+def console(ctx: click.Context) -> None:
+    """Open a debug console where you can run arbitrary commands.
+
+    You will have a `client` and can run commands such as dir(client) to
+    understand what methods are available. Another example is to list all
+    shards via `client.cat.shards('all-current')`.
+
+    This is meant for interactive development and debugging work, not as a
+    replacement for building out essential tim_os features.
+    """
+    client = ctx.obj["CLIENT"]
+    click.echo("Entering debug console. Exit by typing `c` then `enter`")
+    tim_os.console(client)

tim/opensearch.py

@@ -407,3 +407,19 @@ def bulk_index(
     )
     logger.debug(response)
     return result
+
+# Debug Console functions
+
+
+def console(client: OpenSearch) -> None:
+    """Open a debug console where you can run arbitrary commands.
+
+    This is useful as tim_os handles the aws connection information to simplify
+    the process of credentialling in the event we need to use features not yet
+    built into tim_os.
+    """
+    logger.debug("Entering debug mode with client '%s'", client)
+
+    import pdb
+
+    pdb.set_trace()