feat: OPNSense Topology useful to interact with only an opnsense instance.

With this work, no need to initialize a full HAClusterTopology to run
opnsense scores.

Also added an example showing how to use it and perform basic
operations.

Made a video out of it, might publish it at some point!

examples/ha_cluster/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "example-ha-cluster"
+edition = "2024"
+version.workspace = true
+readme.workspace = true
+license.workspace = true
+publish = false
+
+[dependencies]
+harmony = { path = "../../harmony" }
+harmony_tui = { path = "../../harmony_tui" }
+harmony_types = { path = "../../harmony_types" }
+cidr = { workspace = true }
+tokio = { workspace = true }
+harmony_macros = { path = "../../harmony_macros" }
+log = { workspace = true }
+env_logger = { workspace = true }
+url = { workspace = true }
+harmony_secret = { path = "../../harmony_secret" }
+brocade = { path = "../../brocade" }
+serde = { workspace = true }