Improve ENUM collection

[VojtechVitek]

Can we simplify ENUM collection? Instead of defining the gospeak.Enum[uint8] type with a special name = value comments above it..

It'd be great if gospeak could collect iotas directly and webrpc only generated String()/FromString()/MarshalText()/UnmarshalText() methods.

type Sentiment gospeak.Enum[uint8]

const (
	SentimentUnknown  Sentiment = 0 // "unknown"
	SentimentPositive Sentiment = 1 // "positive"
	SentimentNegative Sentiment = 2 // "negative"
	SentimentNeutral  Sentiment = 3 // "neutral"
	SentimentMixed    Sentiment = 4 // "mixed"
)