Include stdint.hh everywhere that uses (u)int[NN]_t types

[neilcook]

Debian package building is failing for some folks due to missing defines integer types e.g. uint64_t (#462 ). This PR includes stdint.h in every file that uses these types.

Note that strictly speaking <cstdint> should be used, but that is not guaranteed to include the types in the global namespace.

Using <cstdint> and prefixing everything with std:: is a future task.

[github-actions]

Test Results

  2 files  ±0    2 suites  ±0   33m 22s ⏱️ +5s
 73 tests ±0   73 ✅ ±0  0 💤 ±0  0 ❌ ±0 
146 runs  ±0  146 ✅ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit a2f57ec. ± Comparison against base commit 5d13229.

♻️ This comment has been updated with latest results.