increase sleep time in cache test and flush test output

[kevinAlbs]

Summary

• Increase sleep time in _test_encrypt_cache_expiration.
• Flush stdout and stderr in tests to fix test log output.

Verified by this patch build. The debian-package-build* task failures appear unrelated.

Background & Motivation

The sleep time in _test_encrypt_cache_expiration is increased from 2ms to 10ms to address observed test failures on Windows tasks. I expect this is due to the coarse resolution of bson_get_monotonic_time on Windows: CDRIVER-4526. bson_get_montonic_time is used to check the current time. Pending CDRIVER-4526, the test is updated to increase the sleep time to 20ms.

TEST_PRINTF and TEST_STDERR_PRINTF macros are added to flush stdout and stderr. This is intended to fix mixed log output from stdout and stderr. Before:

[2025/01/03 09:20:41.815] End test 'NIST CAVP No 'real' csfle library is available. The _test_encrypt_csfle_no_needs_markings test is a no-op.C:\data\mci\17866ad9f3891046e65d08db63c551ae\libmongocrypt\test\test-mongocrypt-ctx-encrypt.c:774 _test_encrypt_cache_expiration(): precondition failed: mongocrypt_ctx_state(ctx) == MONGOCRYPT_CTX_NEED_MONGO_KEYS

After:

[2025/01/07 16:29:44.388]   begin _test_encrypt_cache_expiration
[2025/01/07 16:29:44.388] C:\data\mci\01ac186cc57bfcd8230260d4e398ff47\libmongocrypt\test\test-mongocrypt-ctx-encrypt.c:774 _test_encrypt_cache_expiration(): precondition failed: mongocrypt_ctx_state(ctx) == MONGOCRYPT_CTX_NEED_MONGO_KEYS

Source files in kms-message are not currently formatted to the current .clang-format. This PR does not attempt to reformat. I used the .clang-format file from 8c9ed66 and ignored format-only diffs.

[eramongodb]

Minor feedback; otherwise, LGTM.