Auth Server User Password Mqtt (#113)

## Purpose

A sample to provide basic username password authentication for AIO MQTT
broker.

## Does this introduce a breaking change?
<!-- Mark one with an "x". -->
```
[ ] Yes
[x] No
```

## Pull Request Type
What kind of change does this Pull Request introduce?

<!-- Please check the one that applies to this PR using "x". -->
```
[ ] Bugfix
[x] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Documentation content changes
[ ] Other... Please describe:
```

## How to Test

Follow Readme Instructions.

---------

Signed-off-by: Suneet Nangia <[email protected]>
Co-authored-by: Andrew Malkov <[email protected]>

Author: suneetnangia

samples/auth-server-user-pass-mqtt/.devcontainer/bootstrap.sh

@@ -0,0 +1,10 @@
+# Updates latest stable toolchain for Rust and clippy/fmt for this toolchain
+rustup update stable && rustup default stable && rustup component add clippy rustfmt
+
+# Install kubectl
+curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
+chmod +x kubectl
+mv kubectl /usr/local/bin/
+
+# Install Azure CLI
+curl -sL https://aka.ms/InstallAzureCLIDeb | sudo bash

samples/auth-server-user-pass-mqtt/.devcontainer/devcontainer.json

@@ -0,0 +1,34 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the
+// README at: https://github.com/devcontainers/templates/tree/main/src/ubuntu
+{
+	"name": "MQTT Username Password Auth Server Dev",
+	"image": "mcr.microsoft.com/devcontainers/rust:1-bookworm",
+	// Use 'forwardPorts' to make a list of ports inside the container available locally.
+	// "forwardPorts": [],
+	// Use 'postCreateCommand' to run commands after the container is created.
+	"postCreateCommand": "sh ./.devcontainer/bootstrap.sh",
+	// Configure tool-specific properties.
+	// "customizations": {},
+	"features": {
+		"docker-in-docker": {
+			"version": "latest"
+		}
+	},
+	// More info: https://aka.ms/dev-containers-non-root.	
+	"remoteUser": "vscode",
+	// Add the IDs of extensions you want installed when the container is created.	
+	"customizations": {
+		"vscode": {
+			"extensions": [
+				"rust-lang.rust-analyzer",
+                "redhat.vscode-yaml",
+				"tamasfe.even-better-toml",
+				"vadimcn.vscode-lldb",
+				"streetsidesoftware.code-spell-checker",
+				"ms-vscode.makefile-tools",
+				"davidanson.vscode-markdownlint",
+				"ms-kubernetes-tools.vscode-kubernetes-tools"
+			]
+		}
+	}
+}

samples/auth-server-user-pass-mqtt/.gitignore

@@ -0,0 +1,15 @@
+# Rust
+target/
+**/*.rs.bk
+
+# Generated by Cargo
+Cargo.lock
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
+
+# If you're using IDEs:
+.idea/
+.vscode/
+*.swp
+*.swo