Enumeration are not idomatic

[Guiguiprim]

It is recommended to prefix enum variant with the enum name in ptotobuf for better support in some languages as such:

enum RuleLevel {
    RULE_LEVEL_UNKNOWN = 0;
    RULE_LEVEL_INFORMATIONAL = 1;
    RULE_LEVEL_LOW = 3;
    RULE_LEVEL_MEDIUM = 4;
    RULE_LEVEL_HIGH = 5;
    RULE_LEVEL_CRITICAL = 6;
}

But in Rust it would be more idomatic to remove the prefix and CamelCase the variant as such:

enum RuleLevel {
    Unknown,
    Informational,
    Low,
    Medium,
    High,
    Critical,
}

This is what prost does for example.