daemon: move directory setup into `SetUpTest`
daemon: move directory setup into `SetUpTest`

Setting up the directories and associated configuration per-test means
that there is less global state to worry about that may leak between
tests if the configuration was set up in `SetUpMain`. Factor out this
setup into a function for better readability and move it into `SetUpTest`.

Signed-off by: Ian Vernon <ian@cilium.io>

tklauser/cilium,cilium-team/cilium,cilium/cilium,tgraf/cilium,cilium-team/cilium,tklauser/cilium,michi-covalent/cilium,michi-covalent/cilium,tklauser/cilium,michi-covalent/cilium,cilium/cilium,tklauser/cilium,tgraf/cilium,tgraf/cilium,tgraf/cilium,cilium/cilium,michi-covalent/cilium,cilium/cilium,michi-covalent/cilium,tgraf/cilium,tgraf/cilium,tklauser/cilium,cilium/cilium