Java, updates JsonSchema + List/MapSchemaValidator validate methods

[spacether]

Java, updates JsonSchema + List/MapSchemaValidator validate methods
These methods are being adjusted to accept almost any input data to pave the way for

• future ingestion of json data whee it is a list of any data or a map of any data

Updates

• adds general validate methods to all schemas which accepts and returns @Nullable Object
• uses new validate method to run the failing test cases where invalidly typed input arguments are passed
• schema docs updated to show new validate method signature

Note: Strictly typed ingestion will be done with the future list and map builder classes

PR checklist

• Read the contribution guidelines.
• Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
• Run the following to build the project and update samples:

  mvn clean package 
  ./bin/generate-samples.sh
  ./bin/utils/export_docs_generators.sh
  

  Commit all changed files.
  This is important, as CI jobs will verify all generator outputs of your HEAD commit as it would merge with master.
  These must match the expectations made by your contribution.
  You may regenerate an individual generator by passing the relevant config(s) as an argument to the script, for example ./bin/generate-samples.sh bin/configs/python*.
  For Windows users, please run the script in Git BASH.