BedrockAnthropicTokenUsageCallbackHandler does not have cost information for Claude 4 Sonnet and Claude 4 Opus models

[AsifMehmood97]

The BedrockAnthropicTokenUsageCallbackHandler currently does not include cost calculation logic for the following Claude 4 models. Token usage is tracked, but costs are not estimated, which limits observability and billing transparency when using these newer models via Amazon Bedrock.

The callback handler should include per-model cost mapping and logic for these Claude 4 variants, similar to other supported models, so that both token usage and cost metrics can be accurately reported.