Change `FloatingIpCreate` `address` field to `ip` to match everything else

[david-crespo]

We should pick one or the other. To me, ip is clear and short and seems to be used in more places, but has the grammatical issue of being the IP of a FloatingIp. If that's fine we should probably stick with it. I don't like address as much.

omicron/nexus/types/src/external_api/params.rs

Lines 879 to 891 in e1c3dd7

	pub struct FloatingIpCreate {
	#[serde(flatten)]
	pub identity: IdentityMetadataCreateParams,
	/// An IP address to reserve for use as a floating IP. This field is
	/// optional: when not set, an address will be automatically chosen from
	/// `pool`. If set, then the IP must be available in the resolved `pool`.
	pub address: Option<IpAddr>,
	/// The parent IP pool that a floating IP is pulled from. If unset, the
	/// default pool is selected.
	pub pool: Option<NameOrId>,
	}

omicron/nexus/types/src/external_api/views.rs

Lines 369 to 379 in e1c3dd7

	pub struct FloatingIp {
	#[serde(flatten)]
	pub identity: IdentityMetadata,
	/// The IP address held by this resource.
	pub ip: IpAddr,
	/// The project this resource exists within.
	pub project_id: Uuid,
	/// The ID of the instance that this Floating IP is attached to,
	/// if it is presently in use.
	pub instance_id: Option<Uuid>,
	}

The above is the user-facing disparity, but notably, the DB model and table use ip.

omicron/nexus/db-model/src/external_ip.rs

Lines 131 to 141 in e1c3dd7

	pub struct FloatingIp {
	#[diesel(embed)]
	pub identity: FloatingIpIdentity,
	pub ip_pool_id: Uuid,
	pub ip_pool_range_id: Uuid,
	pub is_service: bool,
	pub parent_id: Option<Uuid>,
	pub ip: IpNetwork,
	pub project_id: Uuid,
	}

omicron/schema/crdb/dbinit.sql

Lines 1726 to 1727 in e1c3dd7

	/* The actual external IP address. */
	ip INET NOT NULL,

[taspelund]

I expected to be quite opinionated about the terminology here, but I'm surprisingly not. I think as long as we're consistent about using the same type and nomenclature everywhere, the actual nomenclature doesn't matter to me a whole lot.

Perhaps unrelated, but I think both ip and address get the point across in a version-agnostic (IPv4 / IPv6) fashion... assuming we want this API to eventually support both v4 and v6.

[david-crespo]

I believe the API already supports v4 and v6.