Static Thread methods and signal methods have been deprecated. Remove
all references in the main code, and most of the tests. Some tests of
the deprecated APIs themselves remain.
Since target specific ticker drivers are not ready also features which uses ticker in upper layers may not work correctly and tests for these features.
We need to disable also failing higher level ticker related tests (by adding check if DEVICE_USTICKER symbol is available and raise #error [NOT_SUPPORTED] if not).