React to API review feedback for dotnet metrics in otel format

This is the API review feedback for https://github.com/lmolkova/semantic-conventions/pull/1

API review notes:

- We think `aspnet.` should be replaced with `aspnetcore.` in all places.
- We prefer prefixing SignalR server metrics with `signalr.server.` rather than `signalr_http_transport.server.`.
- We prefer prefixing custom Kestrel metrics with `kestrel.` rather than `aspnet.kestrel.` or `aspnetcore.kestrel.`.

Open Questions:

- Can we we always supply `network.transport` even if it's the "tcp" default"?
- Why use `server.socket.address` over `server.address` attribute in `kestrel.active_connections` and other Kestrel metrics?
- Do any of these have a `metric.` and/or `dotnet.` prefix? They appear to in the markdown comments and yaml.
- Do we need `tls.protocol.name` if using any SSL version with SslStream on dotnet 8 and above is impossible?

@JamesNK