Update Logtalk language syntax support

Summary: Update Logtalk language syntax support for the latest language specification (3.19.0).

Test Plan:
Tested using the sample Logtalk source file available at:

https://github.com/LogtalkDotOrg/logtalk3/tree/master/coding/tests

Reviewers: dhaumann, cullmann, vkrause, Framework: Syntax Highlighting, Kate

Reviewed By: dhaumann, cullmann, Framework: Syntax Highlighting, Kate

Subscribers: kwrite-devel, kde-frameworks-devel, pmoura

Tags: Framework: Syntax Highlighting, Kate, Frameworks

Differential Revision: https://phabricator.kde.org/D14593