Add OpenTelemetry integration

[maarcingebala]

For production usage, we would like to provide better observability. Currently, only some logging is available, but ideally, we would like to utilize traces and metrics. To support this, we should add integration with OpenTelementry. As a scope for this task, propose the structure of the integration at the code level, propose traces and metrics. Example:

• trace all MCP server calls by clients, such as initialization, tool listing, and calling specific tools
• trace requests to Saleor API
• metrics to measure tools execution time and count

[AjmalPonneth]

@maarcingebala, kindly check the PR and advise