add toolgroup cli commands

[dineshyv]

add llama stack client subcommand for tool groups

test plan:

llama-stack-client toolgroups list
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━┳━━━━━━━━━━━━━━┓
┃ identifier                ┃ provider_id            ┃ args ┃ mcp_endpoint ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━╇━━━━━━━━━━━━━━┩
│ builtin::code_interpreter │ code-interpreter       │ None │ None         │
│ builtin::memory           │ memory-runtime         │ None │ None         │
│ builtin::websearch        │ tavily-search          │ None │ None         │
│ mcp-memory                │ model-context-protocol │ None │ None         │
│ brave-search              │ model-context-protocol │ None │ None         │
└───────────────────────────┴────────────────────────┴──────┴──────────────┘

[ashwinb]

nits:

• the table for toolgroup get should be presented alternately because it is too long horizontally.
• the parameters column should be presented better also so it is easier to parse.