Performance monitoring support in Ktor Client

[buenaflor]

Problem Statement

This issue is a follow up on #25.

As Ktor Client is currently a very popular (probably even the most popular) solution for network clients on KMP, it might be good to add support for instrumenting performance monitoring on Ktor client.

Currently blocked by #83

Solution Brainstorm

OpenTelemetry already has an example: https://github.com/open-telemetry/opentelemetry-java-instrumentation/blob/0f87eaf3d6a769a7ef3e3c5c2bf7457eaf0e3e9d/instrumentation/ktor/ktor-2.0/library/src/main/kotlin/io/opentelemetry/instrumentation/ktor/v2_0/client/KtorClientTracing.kt#L6