Add CMake options to make build process more flexible

Summary:
The following parts might be switched on/off independently:

1. Surveys targeting expressions
2. PHP-related functionality
3. Testing
4. Documenting
5. CLI
6. Console

This aims the following targets:

1. Increase build speed in some cases
2. Avoid extra dependencies of unused functionality
3. Build only required parts

The default behavior is not changed.

Reviewers: vkrause

Reviewed By: vkrause

Differential Revision: https://phabricator.kde.org/D23491