uacme: add support for user-provided setup and cleanup scripts
Add possibility for user to provide setup and cleanup scripts for
additional flexibility. Setup-script takes precedence over the built-in
behavior of uacme.
This helps users with more complex use-cases to utilize uacme to update
certificates without adding complexity to the provided run.sh script.
Signed-off-by: Antti Seppälä <a.seppala@gmail.com>