arch: arm64: implement `arch_stack_walk()`

Currently it supports `esf` based unwinding only.

Then, update the exception stack unwinding to use
`arch_stack_walk()`, and update the Kconfigs & testcase
accordingly.

Also, `EXCEPTION_STACK_TRACE_MAX_FRAMES` is unused and
made redundant after this change, so remove it.

Signed-off-by: Yong Cong Sin <ycsin@meta.com>
Signed-off-by: Yong Cong Sin <yongcong.sin@gmail.com>