Allow excluding options from default verbosity

[hansjansen2]

For example I have removed the context by doing:
verbose=blank,header,footnote,label,new-id,affected,edit,special,project,sync,unwait
but this is not as nice as something like:
verbose_exclude=context
Because it keeps the other default settings intact in case in the feature things are displayed differently.

https://taskwarrior.org/docs/verbosity/

[djmitche]

I suspect we should replace this string config with separate configs for each kind of verbosity e.g., verbose.header. That would allow overriding them individually.

[smemsh]

You could use + and - prefixes to override maybe with less changes:

verbose=-context,+new-id

is the defaults without context, and with new-id. Whereas specifying any without a prefix would start from the specified set rather than the defaults (I think it does this already).