Refactor more tests to minimise forge app initialisation

[knolleary]

Part of #2004

More tests refactored.

• test/unit/forge/ee/routes/billing/index_spec.js
• test/unit/forge/routes/api/application_spec.js
• test/unit/forge/ee/routes/sharedLibrary/index_spec.js

Reduced 50s to 10s

[Steve-Mcl]

An odd failure in this one Nick.

At a quick glance, it looks like an edge case rounding error?

[knolleary]

@Steve-Mcl I've rerun and they have passed up to the point of memory failure.

The previous error must be a timing thing - but in a completely unrelated test. Not sure we've seen it much if at all. As it is unrelated to this PR, I'm happy to move forward as is.

[Steve-Mcl]

Not sure we've seen it much if at all. As it is unrelated to this PR, I'm happy to move forward as is.

Agreed and it is a fairly benign issue (what is one second dfif in a time duration string - in the grand scheme of things)

Happy to proceed.