aoc2024: Implement day8 solution

I did not feel like optimizing this one, so its a O(n^2) looking over
every cell in the grid. Performs way faster than my optimized day6
solution tho :DD

userspace/aoc2024/day8/CMakeLists.txt

@@ -0,0 +1,9 @@
+set(SOURCES
+	main.cpp
+)
+
+add_executable(aoc2024_day8 ${SOURCES})
+banan_include_headers(aoc2024_day8 ban)
+banan_link_library(aoc2024_day8 libc)
+
+install(TARGETS aoc2024_day8 OPTIONAL)