fix: explicit fields for CreateSecurityGroupRequest

[si-mm]

Change the CreateSecurityGroupRequest to include fields of specific data required for creating a security group. This deviates from the request objects only using a "Template" field. The idea is here is so that manifold has an explicit contract and handles marshaling. This PR's implementation of marshaling could be improved (e.g. helper funcs) but this is more of a POC.

Status quo requires the caller of manifold to marshal a string payload everywhere.

Could this be a pattern we want to follow going forward?

Moving forward with SetTemplate() by the caller. This PR just adds new security group rules.

[masonkatz]

What is the universe of fields in the template?

[si-mm]

The basic fields I've interacted with are:

name
description
group     

rule {
    protocol
    rule_type
}

Not all are needed or required for creating a security group.

After looking at my changes again, we could keep Template and use it as an escape hatch until most/all fields are supported.

[si-mm]

I kept the template field just in case. And I can see cases made as to where the ini-like template format should be serialized. In the manifold client or sifi backend.

I believe since the manifold client/api has it's own json interface, it should stick with that and let the backend take said json payload and generate the according template data. Either via the Template field or the various other fields provided.