feat: add llama stack rm command (#2127)

# What does this PR do?
[Provide a short summary of what this PR does and why. Link to relevant
issues if applicable.]

```
llama stack rm llamastack-test
```

[//]: # (If resolving an issue, uncomment and update the line below)
[//]: # (Closes #[issue-number])
#225 

## Test Plan
[Describe the tests you ran to verify your changes with result
summaries. *Provide clear instructions so the plan can be easily
re-executed.*]

[//]: # (## Documentation)

llama_stack/cli/stack/list_stacks.py

@@ -0,0 +1,56 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+import argparse
+from pathlib import Path
+
+from llama_stack.cli.subcommand import Subcommand
+from llama_stack.cli.table import print_table
+
+
+class StackListBuilds(Subcommand):
+    """List built stacks in .llama/distributions directory"""
+
+    def __init__(self, subparsers: argparse._SubParsersAction):
+        super().__init__()
+        self.parser = subparsers.add_parser(
+            "list",
+            prog="llama stack list",
+            description="list the build stacks",
+            formatter_class=argparse.ArgumentDefaultsHelpFormatter,
+        )
+        self._add_arguments()
+        self.parser.set_defaults(func=self._list_stack_command)
+
+    def _get_distribution_dirs(self) -> dict[str, Path]:
+        """Return a dictionary of distribution names and their paths"""
+        distributions = {}
+        dist_dir = Path.home() / ".llama" / "distributions"
+
+        if dist_dir.exists():
+            for stack_dir in dist_dir.iterdir():
+                if stack_dir.is_dir():
+                    distributions[stack_dir.name] = stack_dir
+        return distributions
+
+    def _list_stack_command(self, args: argparse.Namespace) -> None:
+        distributions = self._get_distribution_dirs()
+
+        if not distributions:
+            print("No stacks found in ~/.llama/distributions")
+            return
+
+        headers = ["Stack Name", "Path"]
+        headers.extend(["Build Config", "Run Config"])
+        rows = []
+        for name, path in distributions.items():
+            row = [name, str(path)]
+            # Check for build and run config files
+            build_config = "Yes" if (path / f"{name}-build.yaml").exists() else "No"
+            run_config = "Yes" if (path / f"{name}-run.yaml").exists() else "No"
+            row.extend([build_config, run_config])
+            rows.append(row)
+        print_table(rows, headers, separate_rows=True)