Add tool definition and other tool-related attributes in invoke-agent, inference, and execute-tool spans

[ShipraJain01]

Copied from #2528

This PR extends OpenTelemetry semantic conventions to capture of inputs, outputs, and tool definitions in GenAI Single-Agent and Multi-Agent systems.

###Proposed Additions:
Add tool definitions and execution details for Single and Multi-Agent systems.

Add 'gen_ai.tool_definitions' attribute to 'gen_ai.invoke_agent' span
Add 'gen_ai.tool_definitions' attribute to 'attributes.gen_ai.inference.client' attribute group.
Add 'gen_ai.tool.call.arguments' and 'gen_ai.tool.call.result' attributes to 'gen_ai.execute_tool' span.
Prototype in Semantic Kernel: Link

Prototype in Langgraph: Link

This PR is based on discussions and feedback from previous PR - #2528 Link

Merge requirement checklist

• CONTRIBUTING.md guidelines followed.
• Change log entry added, according to the guidelines in When to add a changelog entry.
  • If your PR does not need a change log, start the PR title with [chore]
• Links to the prototypes or existing instrumentations (when adding or changing conventions)

[ShipraJain01]

@lmolkova : Since we have resolved all open comments and all checks passed, could I please request you to merge this PR.