fix(build): Address various compiler warnings (ULL, const-correctness, Wformat)

[jesper-olsen]

Description of Change

Summary

This Pull Request addresses several compiler warnings found when compiling the repository with strict compiler flags (e.g., Clang 17.0.0 on macOS, which uses -Wall). These changes ensure better code quality, portability, and adherence to modern C standards without altering the functionality of the algorithms.

Specific Warnings Fixed

1. Implicit Unsigned Literals (-Wimplicitly-unsigned-literal):
   • Fixed by adding the ULL suffix to large constants in decimal_to_any_base.c and hash_djb2.c.
2. Double/Float Mismatch (-Wabsolute-value):
   • Changed fabsf to the double-precision function fabs in geometry/vectors_3d.c because the variable alpha is of type double.
3. Const-Correctness (-Wincompatible-pointer-types-discards-qualifiers):
   • Applied an explicit cast (const int **) in the main function of modified_binary_search.c to match the function signature, resolving the const-discarding warning.
4. Format Mismatch (-Wformat):
   • Corrected the format specifier for scanf in collatz.c to %llu to correctly read into a uint64_t.
   • Corrected the printf format specifier in shell_sort2.c from %.4g (double) to %.4lu (unsigned long) for printing clock_t differences.
5. Misc:
   • Simplified array iteration initialization in prime_factoriziation.c (C99 style initialization inside the for loop).

Thank you for reviewing!

Checklist

• Added description of change
• PR title follows semantic commit guidelines
• Search previous suggestions before making a new one, as yours may be a duplicate.
• I acknowledge that all my contributions will be made under the project's license.

Notes: