feat: add configurable TLS backend selection with native-tls as default (#1541)

Add support for choosing between native-tls and rustls-tls backends
through feature flags, with native-tls as the default for maximum
platform compatibility.

Key changes:
- Add mutually exclusive native-tls and rustls-tls feature flags
- Use conditional compilation to select TLS implementation
- Configure rustls-tls with platform certificate verifier
- Refactor to workspace-based dependency management
- Update CI workflows with improved cross-compilation support
- Add comprehensive TLS backend documentation

The native-tls backend uses system TLS libraries (OpenSSL on Linux,
Secure Transport on macOS, SChannel on Windows) while rustls-tls
provides a pure Rust implementation with platform certificate stores.

.devcontainer/Dockerfile

@@ -8,7 +8,6 @@ ENV CARGO_REGISTRIES_CRATES_IO_PROTOCOL="sparse"
 ENV RUST_BACKTRACE=1
 ENV RUSTFLAGS="-D warnings"
 
-
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \
         git \

.devcontainer/Dockerfile.alpine

@@ -7,7 +7,6 @@ ENV CARGO_REGISTRIES_CRATES_IO_PROTOCOL="sparse"
 ENV RUST_BACKTRACE=1
 ENV RUSTFLAGS="-D warnings -C target-feature=-crt-static"
 
-
 RUN apk add --no-cache \
         git \
         nano\

.devcontainer/devcontainer.json

@@ -1,24 +1,20 @@
 {
   "name": "Librespot Devcontainer",
   "dockerFile": "Dockerfile.alpine",
-	// Use 'postCreateCommand' to run commands after the container is created.
-	//"postCreateCommand": "",
-	"customizations": {
-		// Configure properties specific to VS Code.
-		"vscode": {
-			"settings": {
-				"dev.containers.copyGitConfig": true
-			},
-			"extensions": [
-				"eamodio.gitlens",
-        		"github.vscode-github-actions",
-				"rust-lang.rust-analyzer"
-			]
-		}
-	},
+  "_postCreateCommand_comment": "Uncomment 'postCreateCommand' to run commands after the container is created.",
+  "_postCreateCommand": "",
+  "customizations": {
+    "_comment": "Configure properties specific to VS Code.",
+    "vscode": {
+      "settings": {
+        "dev.containers.copyGitConfig": true
+      },
+      "extensions": ["eamodio.gitlens", "github.vscode-github-actions", "rust-lang.rust-analyzer"]
+    }
+  },
   "containerEnv": {
     "GIT_EDITOR": "nano"
-  }
-	// Uncomment to connect as root instead. More info: https://aka.ms/dev-containers-non-root.
-	// "remoteUser": "root"
- }
+  },
+  "_remoteUser_comment": "Uncomment to connect as root instead. More info: https://aka.ms/dev-containers-non-root",
+  "_remoteUser": "root"
+}