Events v4 serialization v2

[jeromevdl]

Issue #, if available:

Description of changes:

• Adding SES Event
• Updating test library for events v4 and serialization v2

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[andclt]

Thanks @jeromevdl, I'm seeing that the Java CI aws-lambda-java-tests is failing. Could you please move the:

- name: Install serialization with Maven
      run: mvn -B install --file aws-lambda-java-serialization/pom.xml

just above the:

 - name: Install events with Maven
      run: mvn -B install --file aws-lambda-java-events/pom.xml

in the file https://github.com/aws/aws-lambda-java-libs/blob/1f2eb94bad517590133ae08adbb6faac8ee24f3f/.github/workflows/aws-lambda-java-tests.yml?

@msailes made the same change some weeks ago: 6dc161a