Support text indexes

[b1ron]

What should be done?

• https://www.mongodb.com/docs/v7.0/core/indexes/index-types/index-text/
• https://www.postgresql.org/docs/current/textsearch-indexes.html
• https://www.sqlite.org/optoverview.html#the_like_optimization

[boutell]

This issue came up while testing for compatibility with ApostropheCMS.

Full text search indexing is of course not a trivial addition, although Postgres does have such features.