feat(Common/SCM): Add DTO for SCM provider creation

Added the `SourceControlCreateDTO` struct in the Common crate to define the data transfer contract for creating new Source Control providers. This DTO:

1. Implements serialization/deserialization using Serde with PascalCase naming
2. Contains fields for provider ID, label, and repository root URI
3. Uses a custom `URLSerializationHelper` for proper URI handling

This DTO enables communication between the Cocoon extension host and Mountain backend when extensions call `vscode.scm.createSourceControl`, directly supporting the SCM workflow implementation. The RootUri field alignment with VS Code's API ensures compatibility with existing extensions while maintaining type safety through the Vine gRPC layer.

Refs #347db1e

Author: NikolaRHristov

Source/SourceControlManagement/DTO/SourceControlCreateDTO.rs

@@ -0,0 +1,22 @@
+//! # SourceControlCreateDTO
+//!
+//! Defines the DTO for creating a new Source Control provider.
+
+use serde::{Deserialize, Serialize};
+use url::Url;
+
+use crate::Utility::Serialization::URLSerializationHelper;
+
+/// A serializable struct sent from the extension host (`Cocoon`) to the main
+/// host (`Mountain`) when an extension calls `vscode.scm.createSourceControl`.
+#[derive(Serialize, Deserialize, Debug, Clone)]
+#[serde(rename_all = "PascalCase")]
+pub struct SourceControlCreateDTO {
+	/// The unique identifier for this source control provider.
+	pub ID:String,
+	/// The human-readable label for this provider (e.g., "Git").
+	pub Label:String,
+	/// The root URI of the repository this provider is managing.
+	#[serde(with = "URLSerializationHelper")]
+	pub RootUri:Url,
+}