chore: updating available procs in golang example

[gabrielmer]

Description

Updating the golang example with the the newly exposed procedures.

For consistency, copy-pasted the definitions from status-go, which implies the change of some variable names.

Changes

• [x] updated the golang example's available procedures

How to test

In nwaku's root directory, build libwaku and run the example with the following commands

make libwaku
cd examples/golang/
go run waku.go