Since the completion is used to sync with ISR mostly, we should set the
default semantic to ISR-safe. So most user will be happy and don't see
any weird behavior in their codes.
Changes:
- Added `rt_completion_wait_noisr` and
`rt_completion_wait_flags_noisr` functions in `completion.h`,
`completion_comm.c`, `completion_mp.c`, and `completion_up.c`.
- The new APIs allow waiting for completions in non-ISR contexts
while ensuring thread context safety.
- Existing documentation and comments were updated to clarify
usage contexts and emphasize restrictions on ISR usage.
Signed-off-by: Shell <smokewood@qq.com>