Added support for go.d.plugin

Ported from RPM spec:

• added libelf to deps (for ebpf.plugin)
• added golang to makedeps (for go.d.plugin)
• added go.d.plugin & ebpf.plugin support
• ported %caps, via:

url -Ss https://raw.githubusercontent.com/netdata/netdata/master/netdata.spec.in | grep "%caps"

Also:

• remove obsolete --with-zlib option
• added aur/netdata-go-plugins to conflicts