[AdvancedQueryParser] Move semantic handling of tokens to SearchStore

Summary:
The AdvancedQueryParser has no knowledge about the semantics of a
value, while the searchstore can use KFM::PropertyInfo to determine
if the value should be converted to e.g. an integer or a QDateTime.

This allows to e.g. use CreationTime in queries.

Test Plan:
baloosearch 'creationtime>=2010-01-20'
baloosearch 'creationDate>="1997-01-01 10:00:00"' \

AND 'creationDate<=2000-01-01'

Reviewers: Baloo, ngraham

Reviewed By: Baloo, ngraham

Subscribers: kde-frameworks-devel

Tags: Frameworks, Baloo

Differential Revision: https://phabricator.kde.org/D28400