telemetry(amazonq): adding a new metric amazonq_invokeLLM for agentic chat

[laileni-aws]

Problem

• IDE has amazonq_toolUseSuggested metric emitted per tool execution but this count will be high in the future.
• No latency metrics for tool execution.

Solution

• amazonq_invokeLLM is emitted per LLM call in the agentic loop, this emits the list of toolName's, list of toolId's and list of tool execution latencies.

{
            "name": "amazonq_invokeLLM",
            "description": "This metric is emitted per LLM call in the agentic loop with or without tool execution.",
            "metadata": [
                {
                    "type": "credentialStartUrl",
                    "required": false
                },
                {
                    "type": "cwsprChatConversationId"
                },
                {
                    "type": "cwsprChatConversationType"
                },
                {
                    "type": "cwsprToolName"
                },
                {
                    "type": "cwsprToolUseId"
                },
                {
                    "type": "enabled",
                    "required": false
                },
                {
                    "type": "languageServerVersion",
                    "required": false
                },
                {
                    "type": "latency",
                    "required": false
                },
            ]
        },

License

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.