[ocis]enable KQL in ocis

# Description

## User Stories

* > As a student searching for a good file sync solution

## Value

## Acceptance Criteria
- The client can pick by header wich search query dialect should be used
(Legacy or KQL)

## Definition of ready
[ ] everybody needs to understand the value written in the user story
[ ] acceptance criteria has to be defined
[ ] all dependencies of the user story need to be identified
[ ] feature should be seen from an end user perspective
[ ] user story has to be estimated
[ ] story points need to be less then 20

## Definition of done
- Functional requirements
[ ] functionality described in the user story works
[ ] acceptance criteria are fulfilled
- Quality
[ ] code review happened
[ ] CI is green
[ ] critical code received unit tests by the developer
[ ] automated tests passed (if automated tests are not available, this test needs to be created and passed
- Non-functional requirements
[ ] no sonar cloud issues