Rename & Restructure ComponentSelector (#189)

- Rename the field names so both are plural
- Nest the sub-messages and remove "Component" prefix
- Use `Set` suffix
- Add examples

Author: Marenz

proto/frequenz/api/dispatch/v1/dispatch.proto

@@ -302,31 +302,35 @@ message DispatchFilter {
 
 // Parameter for controlling which components a dispatch applies to
 // either a set of component IDs, or a set of component categories.
+// Examples:
+// - To dispatch to a set of component IDs:
+//   selector { component_ids { ids: [1, 2, 3] } }
+// - To dispatch to a set of component categories:
+//   selector { component_categories { categories: [COMPONENT_CATEGORY_BATTERY, COMPONENT_CRYPTO_MINER] } }
 message ComponentSelector {
-  oneof selector {
+  // Wrapper for controlling dispatches with a set of component IDs
+  // Required as we can't use `repeated` directly in a `oneof`
+  message IdSet {
     // Set of component IDs
-    ComponentIDs component_ids = 1;
+    repeated uint64 ids = 1;
+  }
 
-    // Component categories
-    ComponentCategories component_category = 2;
+  // Wrapper for controlling dispatches with a set of component categories
+  // Required as we can't use `repeated` directly in a `oneof`
+  message CategorySet {
+    // Set of component categories
+    repeated frequenz.api.common.v1.microgrid.components.ComponentCategory categories = 1;
   }
-}
 
-// Wrapper for controlling dispatches with a set of component IDs
-// Required as we can't use `repeated` directly in a `oneof`
-message ComponentIDs {
-  // Set of component IDs
-  repeated uint64 component_ids = 1;
-}
+  oneof selector {
+    // Set of component IDs
+    IdSet component_ids = 1;
 
-// Wrapper for controlling dispatches with a set of component categories
-// Required as we can't use `repeated` directly in a `oneof`
-message ComponentCategories {
-  // Set of component categories
-  repeated frequenz.api.common.v1.microgrid.components.ComponentCategory component_categories = 1;
+    // Component categories
+    CategorySet component_categories = 2;
+  }
 }
 
-
 // Ruleset governing when and how a dispatch should re-occur.
 //
 // Timezone Note: Timestamps are in UTC. It is the responsibility of each microgrid to translate UTC