services/haproxy/backend - advanced_backend is in base64 format

[KristijanL]

Describe the bug
i don't know if this is a bug or intentional and just missing documentation, but when creating / updating a haproxy backend the advanced_backend field has to be base64 encoded, and even when retrieving a backend its returned in base64.
In the pfsense GUI its not encoded.

pfSense Version & Package Version:

• pfSense Version: 2.7.2-RELEASE
• Package Version 2.3.1

Affected Endpoints:

• URL: /api/v2/services/haproxy/backend

[jaredhendrickson13]

I'd say this is a bug since the API is able to automatically handle base64 encoding/decoding for values. Problem is this field is currently a regular string field instead of base64 field. Easy fix, but it'll need to go in v2.4.0 instead of a patch since it's potentially a breaking change for existing implementations. Until then, a workaround would be having the client-side handle the base64 encoding/decoding on this field.

[KristijanL]

great, thanks!