* httpcaddyfile: Validates TLS DNS challenge options
Adds validation to the TLS Caddyfile adapter to ensure that when DNS challenge options (such as propagation_delay or dns_ttl) are specified, a DNS provider is also configured.
Adds new integration tests to verify this validation logic, and implements a new mechanism for adapt tests to assert a config adapt error.
* Add some more AI-generated tests asserting config errors
* Parallel doesn't work here, we use global variables
* Windows fix
