feat(Common/SCM): Add DTO for updating SCM group properties

Added `SourceControlGroupUpdateDTO` struct to the `Common` crate to support updating source control group properties without modifying resources. This DTO:
- Defines serializable fields for provider handle, group ID, and label
- Uses PascalCase serialization to align with gRPC conventions in `Vine`
- Enables partial updates of SCM groups (e.g., changing labels/visibility)

This completes the core DTO set for SCM operations following recent additions (`SourceControlGroupUpdateDTO` joins provider creation DTOs). The struct will be used in `Mountain`'s SCM handlers and transmitted via gRPC to `Cocoon` for extension communication, advancing the implemented SCM workflow.

Author: NikolaRHristov

Source/SourceControlManagement/DTO/SourceControlGroupUpdateDTO.rs

@@ -0,0 +1,20 @@
+//! # SourceControlGroupUpdateDTO
+//!
+//! Defines the DTO for updating the properties of an SCM resource group.
+
+use serde::{Deserialize, Serialize};
+
+/// A serializable struct used to update the properties of a source control
+/// group, such as its label or visibility, without affecting its list of
+/// resources.
+#[derive(Serialize, Deserialize, Debug, Clone)]
+#[serde(rename_all = "PascalCase")]
+pub struct SourceControlGroupUpdateDTO {
+	/// The handle of the provider that owns the group.
+	pub ProviderHandle:u32,
+	/// The unique identifier for the group within its provider.
+	pub GroupID:String,
+	/// The new human-readable label for the group.
+	pub Label:String,
+	// Other properties like `HideWhenEmpty` could be added here.
+}