Creating Sites generates warning messages due to implicitly used named defaults section

[georgijd-form3]

Hi,

I'd like to bring your attention to a minor problem with Site objects.

The SiteService and SiteFarm objects don't have a From field which prevents users from specifying a named defaults section to be used when configuring Sites.

The https://github.com/haproxytech/client-native/blob/fd6b9e5b9bdfc053f109e18a5ea284a39e3dffe6/configuration/site.go#L530-L539

and https://github.com/haproxytech/client-native/blob/fd6b9e5b9bdfc053f109e18a5ea284a39e3dffe6/configuration/site.go#L541-L548

methods don't set the https://github.com/haproxytech/client-native/blob/fd6b9e5b9bdfc053f109e18a5ea284a39e3dffe6/models/frontend.go#L139 and https://github.com/haproxytech/client-native/blob/fd6b9e5b9bdfc053f109e18a5ea284a39e3dffe6/models/backend.go#L143 respectively which leads to warnings in HAProxy when applying the configuration:

[WARNING] (1) : config : parsing [/etc/haproxy/haproxy.cfg:48] : defaults section 'defaults' (declared at /etc/haproxy/haproxy.cfg:22) is explicitly referenced by another proxy and implicitly used here. To avoid any ambiguity don't mix both usage. Add a last defaults section not explicitly used or always use explicit references.

This is not ideal because if we try to update a configuration file with an unnamed defaults section, the config parser automatically renames it as unnamed_defaults_1 and updates all existing sections with from unnamed_defaults_1. When we subsequently update the configuration file via dataplaneapi we get the above warning if we don't set the From attribute for all frontend and backend sections we are trying to create, including the ones created through a Site object