Add an E2E test suite specific to the shipper that does the following:

• Add a test where the agent is configured to use the shipper, then downgraded to a version without the shipper.
• Add a test where the agent is configured to use the shipper from startup.
• Add a test where the agent is configured not to use the shipper at startup, then switched over to use.
• Add a test where the agent is configured to use a memory, then switches to the disk queue, then switches back.
• Add a test where the output type is switches from the console output to the ES output and then back to the console output.
• Add a test to ensure that the output can be reloaded without errors or data loss.
• TBD additional test cases

We should also consider defaulting the agent to use the shipper as part of all existing agent E2E test suites to ensure it does not break anything. The existing E2E test suites are defined in https://github.com/elastic/e2e-testing/tree/main/e2e/_suites.