Add a way to change logical operator on basic search

There's a need for a feature allowing to concatenate a string in basic search.

Find a character that would allow users to change logical operator.

added Basic search in in-sylva.search.app Frontend Priority: high labels

moved from in-sylva.search.app#84 (moved)

removed Frontend label

removed Priority: high label

added Backend label

assigned to @remi.bisson

mentioned in merge request !18 (merged)

This is done "automatically" via elasticsearch query configuration. Wildcards allow this kind of search usage.

mentioned in merge request !19