Fix: fix bedrock payload handler for parallel and strict tool use, add fallback for thinking on claude

[cosminacho]

Notes on Claude with Extended thinking:

The react loop we have in the SDK will not work on Claude when enabling extended_thinking due to several reasons:

• Claude needs tool_choice="auto" to work with extended_thinking
• Claude expects a specific interaction format for extended_thinking: input-> ai_message with_tool_calls -> resolve tool calls -> finish the interaction with an ai_message.
• Striping thinking from the model and invoking with force_tool_use can't be done during an 'interaction'.

Solution: I'm working on implementing a custom agentic loop for Claude with thinking
I still need the changes in this PR in order to reautilize the methods and payload handlers.