This change clarifies the documentation of the context completion suggester
regarding filtering and boosting with contexts.
Unlike the suggester v1, filtering on multiple contexts
works as a disjunction, a suggestion matches if it contains at least one of the provided
context values and boosting selects the maximum score among the matching contexts.
This commit also adapts an old test that was written for the v1 suggester and commented out
for version 2 because the behavior changed.
4561c5ee83