Feature/show prices

[chrisnestrud]

This is for showing per-token model price information. For example:

$ cecli --models openai/gpt-5.2
────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
Models which match "openai/gpt-5.2":
- openai/gpt-5.2 ($1.75/1m/input, $14.00/1m/output)
- openai/gpt-5.2-2025-12-11 ($1.75/1m/input, $14.00/1m/output)
- openai/gpt-5.2-chat-latest ($1.75/1m/input, $14.00/1m/output)
- openrouter/openai/gpt-5.2 ($1.75/1m/input, $14.00/1m/output)
- openrouter/openai/gpt-5.2-chat ($1.75/1m/input, $14.00/1m/output)
- openrouter/openai/gpt-5.2-pro ($21.00/1m/input, $168.00/1m/output)