Generate helpers with deprecated annotations

[gfx]

From the beginning of Orma, it does not generates query helper methods for columns without indexed = true.

I believe this is one of the most useful inventions of Orma, but on the other hand, it is confusing for Orma beginners and there are few hints to generate these helpers.

Instead, with this PR Orma always generates helpers for all the columns, but add @Deprecated if a column is not indexed, meaning "you can use it but is not recommended".