Add Append Transformation

[miles-grant-ibigroup]

Checklist

• [x] Appropriate branch selected (all PRs must first be merged to dev before they can be merged to master)
• [x] Any modified or new methods or classes have helpful JavaDoc and code is thoroughly commented
• [x] The description lists all applicable issues this PR seeks to resolve
• [x] The description lists any configuration setting(s) that differ from the default settings
• [x] All tests and CI builds passing

Description

Adds new transformation type similar to replace transformation that appends to file instead of replaces. Appending is done in temporary dir. Unit test is included

[miles-grant-ibigroup]

Thanks all changes are addressed!