Support EAB without challengetype

[gvde]

Sectigo and Harica (and possibly others) support acme with eab without requiring a challengetype. The names allowed for the request are configured for the acme account.

Currently, we have to set a fake CHALLENGETYPE and comment out the first line of verify_config to use dehydrated.

[sbdlt]

Same situation here.

No need to comment a line in verify_config, you can just use an existing challenge type and add a comment in the config file to remember that this has no use. No challenge will be made if the ACME endpoint does not need it.

[gvde]

Same situation here.

No need to comment a line in verify_config, you can just use an existing challenge type and add a comment in the config file to remember that this has no use. No challenge will be made if the ACME endpoint does not need it.

Not quite. If you set "http-01" you have to define a WELLKNOWN, if you use "dns-01" you have to define a HOOK. Only for "tls-alpn-01" it would not require anything else. Either way, it's not nice nor intuitive.