Improve PostgrestFilterBuilder Semantics for work in Swift

[chFlorian]

Feature request

Right now the PostgrestFilterBuilder mirrors the Javascript API design. This might work great there, but it's not the kind of descriptive semantics that Swift users are used to.

phfts(column: column, query: query, config: config)

Without knowing any context it is impossible to understand (and even then hard to read) what this expression does.

Describe the solution you'd like

More descriptive function names would be great.

phrasetoFullTextSearch(column: String, query: String, config: String? = nil)