[cmd/telemetrygen] Add support for metric name/attributes customization

[claudiobastos]

Component(s)

cmd/telemetrygen

Is your feature request related to a problem? Please describe.

So far we can't set metrics attributes or customize it's name

Describe the solution you'd like

I would like to customize metrics attributes in order to improve toolchain and ecosystem

Describe alternatives you've considered

No response

Additional context

No response

[github-actions]

Pinging code owners:

• cmd/telemetrygen: @mx-psi @codeboten

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[crobert-1]

A code owner has stated support for the idea in the submitted PR, so I've removed the needs triage label.