subsystem: kernel_shell: extend thread info

1) Dump time sinse last scheduler call
Could be handy for tickless kernel debug.
Will indicate that no rtc irq is called

2) Dump current timeout of each thread
Could be used to find yout when thread will wake up

3) Dump human friendly thread state

4) Use shell_prin instead shell_fprintf

Signed-off-by: Pavlo Hamov <pavlo_hamov@jabil.com>