lib: min_heap: Add min-heap data structure

Introduce a binary min-heap implementation as a generic data structure
for use in kernel and application code. A min-heap always maintains
the smallest element at the root, making insertion and removal of the
minimum element efficient (O(log n)).

The API allows both static and dynamic initialization, supports custom
comparators.

Signed-off-by: Sayooj K Karun <sayooj@aerlync.com>