fix(freertos): Limit idle task name length copy operation and ensure null-termination...

fix(freertos): Limit idle task name length copy operation and ensure null-termination of the idle task name string (#1203)

* fix(freertos): Limit idle task name copy operation and ensure null termination

This commit:
- Limits the idle task name length copy operation to prevent
  Out-of-bounds memory access warnings from static code analyzers.
- Fixes a bug where in the idle task name could be non null-terminated
  string for SMP configuration.

Signed-off-by: Sudeep Mohanty <sudeep.mohanty@espressif.com>