Migrate the Go Library from AppOptics to SolarWinds Observability SaaS

All appoptics-apm-go versions are based on proprietary code. Starting with apm-go version 1.0.0, the library is built on top of OTel.

To migrate from AppOptics to SolarWinds Observability SaaS, follow the Uninstall instructions and remove the appoptics-apm-go module from your application. Then set up apm-go as described in Install the Go Library.

Other differences

The AppOptics config file is not yet supported. All configuration options should be updated to use the new environment variables.

All instrumentation calls must be updated to use the OpenTelemetry API or the swo package API.