Add support for input and output artifacts in the Lambda invoke CodePipeline Action

[skinny85]

According to the reference documentation, a Lambda Action can have up to 5 inputs, and up to 5 outputs. We should allow modeling these in the Action.

Reported by @defel on our Gitter channel.

[aweiher]

Quoting discussion from gitter channel:

@defel [...] BTW, can you elaborate how do input artifacts work with Lambda Invoke Actions? How are the artifacts passed to the Lambda?

@skinny85 here is an example lambda function:

exports.handler = async (event) => {
    console.log('EV:', JSON.stringify(event));
    
    // .. handle codepipeline input artifacts ..
    // .. s3 upload output artifacts .. 
}

which outputs the following event:

{
    "CodePipeline.job": {
        "id": "ae5410b4-f587-4440-81fe-63754c01beb4",
        "accountId": "123123213",
        "data": {
            "actionConfiguration": {
                "configuration": {
                    "FunctionName": "InfrastructureStack-MyServiceDevEclECSECSClusterDe-JKL1ZHL8PE45"
                }
            },
            "inputArtifacts": [
                {
                    "location": {
                        "type": "S3",
                        "s3Location": {
                            "objectKey": "TEST_ecr-deploy-pipe/SourceArti/A0NL7zF",
                            "bucketName": "codepipeline-eu-central-1-123123213"
                        }
                    },
                    "revision": "sha256:ed82e395895e03986043c5c5dffc009f9bc5be00485318693bfd1941596f3b87",
                    "name": "SourceArtifact"
                }
            ],
            "outputArtifacts": [
                {
                    "location": {
                        "type": "S3",
                        "s3Location": {
                            "objectKey": "TEST_ecr-deploy-pipe/imageJson/1TQ1xBg",
                            "bucketName": "codepipeline-eu-central-1-123123213"
                        }
                    },
                    "revision": null,
                    "name": "imageJson"
                }
            ],
            "artifactCredentials": {
                "...": "..."
        }
    }
}

The job of the lambda function is now to upload the OutputArtifact (as as zip-file) like this (not tested but should work like this):

exports.handler = async (event) => {
    // input artifacts example:
    const inputArtifactLocation = ev["CodePipeline.job"].data.inputArtifacts[0].location.s3Location

    // output artifacts example: 
    const {bucketName, objectKey} = event["CodePipeline.job"].data.outputArtifacts[0].location.s3Location

    // user parameter example:
    const key = ev["CodePipeline.job"].data.actionConfiguration.configuration.UserParameters

    // upload output artifact to artifact-bucket:
    return s3.putObject({
        Bucket: bucketName,
        Key: objectKey,
        Body: // TODO: ... zip file ...
    }).promise().then(() => putJobSuccessResultAsync({
        jobId: event["CodePipeline.job"].id
    })).then(() => {

To complete this, here is how it looks in the aws console: