Create a way to scan all configured file paths

We often want to do checks on all configured file paths:

• relative paths
• runtime immutability
• sandbox immutability

We need to scan:

• type FILENAME
• HiddenServiceDir
• Log files
• *Port unix sockets
• ControlSocket
• Any options that activate a file path, but don't allow it to be configured (OnionAuth etc.)

Follow up to #32339 (moved) and #32344 (moved).