tests: kernel: pipe: Add new test cases for pipe API rework

This commit adds new test cases for the pipe API rework.
* basic.c: Sanity check for pipe operations.
* concurrency.c: Test pipe operations with multiple threads.
* stress.c: Test pipe operations under stress conditions.

And moves the old pipe test cases to the deprecated folder.

Signed-off-by: Måns Ansgariusson <Mansgariusson@gmail.com>