feat: apply to_tsvector to the filtered columns when a fts operator is used

[laurenceisla]

Closes #2255

When an fts operator is used, then it applies to_tsvector to the filtered column. For example:

/table?column=fts(simple).test

is equivalent to this in SQL:

SELECT *
FROM table
WHERE to_tsvector('simple', column) = to_tsquery('simple', 'test')

If the `totsv` modifier (short for `to_tsvector`) is used for `fts` operators then it applies `to_tsvector` to the filtered column. For example:

/table?column=totsv.fts(simple).test

Is equivalent to this in SQL:

SELECT *
FROM table
WHERE to_tsvector('simple', column) = to_tsquery('simple', 'test')

[steve-chavez]

Great work 💯