Move Layout into adapter class

pr comments, mv package, make work locally.

revert pom change to parent

Rm provided scope - this is problematic for spring-boot-maven plugin to build jar

Detach sample from spring-cloud-function-parent

Update readmes

cleanup

Add comment

fix javadoc
Resolves #518

spring-cloud-function-samples/function-sample-gcp/README.adoc

@@ -35,7 +35,7 @@ Run the following command from the project root to deploy.
 
 ----
 gcloud alpha functions deploy function-sample-gcp \
---entry-point org.springframework.cloud.function.adapter.gcp.FunctionInvoker \
+--entry-point org.springframework.cloud.function.adapter.gcp.GcfJarLauncher \
 --runtime java11 \
 --trigger-http \
 --source target/deploy \