Streamline and refactor the azure and the azure-web adapters.

- Add SCF/Azure Gradle sample and docs.
- Move the function-azure-di-samples into standalone projects.
 - Apply the name convetion and project structure for the SCF adaptes.
   E.g.  function-sample-azure-XXX projects under the spring-cloud-function-samples root.
 - Remove the redudant samples.
 - Improve the samples docs and the Adapter generic docs.
- Streamline docs.
- Add azure web adapter sample and README.
- Add Spring Azure Functions banner for azure and azure web adapters.
- azure-web adapter fixes:
  - Fix issues in serverles-web ProxyHttpServletResponse implementation.
  - Remove the custom FunctionClassUtils utils in favor of scf-context/util/FunctionClassUtils.
- Remove redundant files.
- Add FunctionInvoker deprecation annotations.
- Extend the time trigger sample with Retry policies example.

spring-cloud-function-samples/function-sample-azure-http-trigger-gradle/build.gradle

@@ -0,0 +1,61 @@
+plugins {
+    id 'java'
+    id 'io.spring.dependency-management' version '1.1.0'
+    id "com.microsoft.azure.azurefunctions" version "1.11.0"
+}
+
+apply plugin: 'java'
+apply plugin: "com.microsoft.azure.azurefunctions"
+
+group = 'org.scf.azure'
+version = '0.0.1-SNAPSHOT'
+
+java {
+    sourceCompatibility = '17'
+    targetCompatibility = '17'
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(17)
+    }
+}
+
+jar {
+    manifest {
+        attributes(
+            // The main class is compulsory. Set it to point your SpringBootApplication.
+            "Main-Class": "org.scf.azure.gradle.GradleDemoApplication"
+        )
+    }
+}
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    implementation 'org.springframework.boot:spring-boot-starter'
+    implementation "org.springframework.cloud:spring-cloud-function-adapter-azure:4.0.3"
+}
+
+tasks.named('test') {
+    useJUnitPlatform()
+}
+
+// Configuration options: https://github.com/microsoft/azure-gradle-plugins/wiki/Configuration
+azurefunctions {
+    resourceGroup = 'java-functions-group'
+    appName = 'scff-azure-gradle-sample'
+    region = 'westus'
+    appServicePlanName = 'java-functions-app-service-plan'
+    pricingTier = 'EP1'
+    runtime {
+      os = 'linux'
+      javaVersion = '11'
+    }
+    auth {
+      type = 'azure_cli'
+    }
+    appSettings {
+      FUNCTIONS_EXTENSION_VERSION = '~4'
+    }
+    localDebug = "transport=dt_socket,server=y,suspend=n,address=5005"
+}