feat(logging): implement category-based logging (#1362)

# What does this PR do?

This commit introduces a new logging system that allows loggers to be
assigned
a category while retaining the logger name based on the file name. The
log
format includes both the logger name and the category, producing output
like:

```
INFO     2025-03-03 21:44:11,323 llama_stack.distribution.stack:103 [core]: Tool_groups: builtin::websearch served by
         tavily-search
```

Key features include:

- Category-based logging: Loggers can be assigned a category (e.g.,
  "core", "server") when programming. The logger can be loaded like
  this: `logger = get_logger(name=__name__, category="server")`
- Environment variable control: Log levels can be configured
per-category using the
  `LLAMA_STACK_LOGGING` environment variable. For example:
`LLAMA_STACK_LOGGING="server=DEBUG;core=debug"` enables DEBUG level for
the "server"
    and "core" categories.
- `LLAMA_STACK_LOGGING="all=debug"` sets DEBUG level globally for all
categories and
    third-party libraries.

This provides fine-grained control over logging levels while maintaining
a clean and
informative log format.

The formatter uses the rich library which provides nice colors better
stack traces like so:

```
ERROR    2025-03-03 21:49:37,124 asyncio:1758 [uncategorized]: unhandled exception during asyncio.run() shutdown
         task: <Task finished name='Task-16' coro=<handle_signal.<locals>.shutdown() done, defined at
         /Users/leseb/Documents/AI/llama-stack/llama_stack/distribution/server/server.py:146>
         exception=UnboundLocalError("local variable 'loop' referenced before assignment")>
         ╭────────────────────────────────────── Traceback (most recent call last) ───────────────────────────────────────╮
         │ /Users/leseb/Documents/AI/llama-stack/llama_stack/distribution/server/server.py:178 in shutdown                │
         │                                                                                                                │
         │   175 │   │   except asyncio.CancelledError:                                                                   │
         │   176 │   │   │   pass                                                                                         │
         │   177 │   │   finally:                                                                                         │
         │ ❱ 178 │   │   │   loop.stop()                                                                                  │
         │   179 │                                                                                                        │
         │   180 │   loop = asyncio.get_running_loop()                                                                    │
         │   181 │   loop.create_task(shutdown())                                                                         │
         ╰────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
         UnboundLocalError: local variable 'loop' referenced before assignment
```

Co-authored-by: Ashwin Bharambe <@ashwinb>
Signed-off-by: Sébastien Han <seb@redhat.com>

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

## Test Plan

```
python -m llama_stack.distribution.server.server --yaml-config ./llama_stack/templates/ollama/run.yaml
INFO     2025-03-03 21:55:35,918 __main__:365 [server]: Using config file: llama_stack/templates/ollama/run.yaml           
INFO     2025-03-03 21:55:35,925 __main__:378 [server]: Run configuration:                                                 
INFO     2025-03-03 21:55:35,928 __main__:380 [server]: apis:                                                              
         - agents                                                     
``` 
[//]: # (## Documentation)

---------

Signed-off-by: Sébastien Han <seb@redhat.com>
Co-authored-by: Ashwin Bharambe <ashwin.bharambe@gmail.com>

llama_stack/distribution/stack.py

@@ -11,9 +11,7 @@ import tempfile
 from typing import Any, Dict, Optional
 
 import yaml
-from termcolor import colored
 
-from llama_stack import logcat
 from llama_stack.apis.agents import Agents
 from llama_stack.apis.batch_inference import BatchInference
 from llama_stack.apis.benchmarks import Benchmarks
@@ -39,8 +37,11 @@ from llama_stack.distribution.distribution import get_provider_registry
 from llama_stack.distribution.resolver import ProviderRegistry, resolve_impls
 from llama_stack.distribution.store.registry import create_dist_registry
 from llama_stack.distribution.utils.dynamic import instantiate_class_type
+from llama_stack.log import get_logger
 from llama_stack.providers.datatypes import Api
 
+logger = get_logger(name=__name__, category="core")
+
 
 class LlamaStack(
     VectorDBs,
@@ -101,9 +102,8 @@ async def register_resources(run_config: StackRunConfig, impls: Dict[Api, Any]):
         objects_to_process = response.data if hasattr(response, "data") else response
 
         for obj in objects_to_process:
-            logcat.debug(
-                "core",
-                f"{rsrc.capitalize()}: {colored(obj.identifier, 'white', attrs=['bold'])} served by {colored(obj.provider_id, 'white', attrs=['bold'])}",
+            logger.debug(
+                f"{rsrc.capitalize()}: {obj.identifier} served by {obj.provider_id}",
             )