Tech debt: Refactor RemoteApplication in Integration Tests

[tippmar-nr]

We currently have a number of classes that inherit RemoteApplication, and several of them have nearly identical implementations of Start(). We should look for opportunities to refactor and make the base class more flexible - for example, we might move the code that sets the (long and growing) list of required environment variables to the base class which would simplify the derived class implementations considerably.

There are also likely to be similar overrides of CopyToRemote() that we should try to refactor if it makes sense.

[workato-integration]

https://new-relic.atlassian.net/browse/NR-311700