Restructure integration tests according to the integration level

[Pijukatel]

Currently, there are the following test types:

• pure unit tests (run locally, no API calls or mocked)
• API integration tests (they run locally, but they do API calls)
• Actor on platform integration tests (they build and start an Actor that runs on the platform)
• Actor on platform + Crawler integration tests (they build and start an Actor that contains a Crawler which runs on the platform)

Restructure folder structure to make it clear where new tests belong, maybe update the makefile