[otelhttp] Follow on semconv upgrade work

[MadVikingGod]

The Remaining work for Upgrading the otelhttp semantic convention

• Add semconv to cover client HTTP instrumentation
• Template it to other semconvutil code bases.
  • instrumentation/github.com/emicklei/go-restful/otelrestful/
  • instrumentation/github.com/gin-gonic/gin/otelgin/
  • instrumentation/github.com/gorilla/mux/otelmux/
  • instrumentation/github.com/labstack/echo/otelecho/
  • instrumentation/gopkg.in/macaron.v1/otelmacaron/
  • instrumentation/net/http/httptrace/otelhttptrace/
• Upgrade metrics to v1.24.0 (does not require env swapping)