Added redirect option for activation endpoint

[Max-checkmk]

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

• Redirect option is always set to false in the activation endpoint.
• In the agent role we have a fixed wait time of 30sec after activating changes

What is the new behavior?

• It's now possible to set redirect to true
• In the agent role the activation handler has redirect set to true, so there's no need to wait anymore

Other information

Even with redirect set to true, there is no need to handle the redirect (like with service discovery endpoint).
This works without further changes.

[robin-checkmk]

As discussed outside of GitHub, we will clarify some things internally before moving this forward.
Technically it looks fine, we just want to check, that there are no side effects.
Once that has been cleared, we can merge this for release 4.0.0.