core: introduce evenly distributed int64 random in range

Tarantool codebase had at least two functions to generate random
integer in given range and both of them had problems at least with
integer overflow. This patch brings nice functions to generate random
int64_t in given range without overflow while preserving uniform random
generator distribution using unbiased bitmask with rejection method.
It is now possible to use xoshiro256++ PRNG or random bytes as a basis.
Most relevant replacements have been made. Needed tests are introduced.

Closes #5075