tests: semaphore tests overhaul

Modify current semaphore tests.
I checked the semaphore tests, and find out many gaps.
Overhaul semaphore tests:
1. Modify some tests
2.Doxygen tags update
3. Update text in zassert messages
4. Remove misprints
5. Test cases names change. Some test cases had a semaphore name in
their name, for example simple_sem, I removed it from the test
case names. Also some test cases used sema, some used word sem.
I decided to make standard short word for a semaphore sem

Detailed explanation of the changes:
-test_k_sema_init() -updated name to test_sem_init, updated doxygen
tag, updated zassert text
-test_sem_take_timeout() -updated doxygen tag, added zassert to check
that reset was correct, updated zassert text
-test_sem_take_timeout_fails() -updated doxygen tag, added zassert
to check that reset was correct, updated zassert text
-test_sem_take_timeout_forever() -updated doxygen tag, added zassert
to check that reset was correct, updated zassert text
-test_sem_take_multiple() -updated doxygen tag, modified that test,
added one more thread sem_tid_4, with high priority and added one
more semaphore high_prio_long_sem
-test_simple_sem_from_isr() -updated name to test_sem_give_from_isr,
updated doxygen tag, zassert text fix
-test_simple_sem_from_task() -updated name
to test_sem_give_from_thread, updated doxygen tag, zassert text fix

Tested on qemu_x86, qemu_x86_64, reel_board, and iotdk

Signed-off-by: Maksim Masalski <maksim.masalski@intel.com>