Add ability to annotate messages/fields with nolint directive

[jared2501]

I have some enums/structs that fail lint in my protobuf, for good reason (e.g. I have an enum called X509_KEY_USAGE_DATA_ENCIPHERMENT, and "data encipherment is a phrase taken from IETF spec).

Currently, i skip the entire file by adding it to my prototool.yaml. Instead, I would like to be able to annotate this enum, or even this value in the enum, with a comment that would disable linting for this specific case. golangci-lint offers a // nolint:<rule-name> directive which I find super handy in cases like these. Can prototool learn this skill too?

[smaye81]

Yeah this is a fair request. I will add it to the backlog.

[sysulq]

looking forward to this new feature！