feat: Enhance request struct and add debug logging

[xiaguan]

for wrong usage like this

./bin/cachesim ../data/twitter_cluster52.csv csv lru 1gb 

Output is

../data/twitter_cluster52.csv LRU cache size     1GiB,          1000000 req, miss ratio 0.0000, throughput 2.29 MQPS

Users might find it annoying when there's no error log or anything to go on. It could be helpful to print the first 10 requests to ensure the simulation is reading them correctly.
After this change, output is

[INFO]  08-08-2024 12:59:03 request.h:78   (tid=8459455488): Request: obj_id=0, obj_size=1, ttl=-1, op=invalid
[INFO]  08-08-2024 12:59:03 request.h:78   (tid=8459455488): Request: obj_id=0, obj_size=1, ttl=-1, op=invalid
[INFO]  08-08-2024 12:59:03 request.h:78   (tid=8459455488): Request: obj_id=0, obj_size=1, ttl=-1, op=invalid
[INFO]  08-08-2024 12:59:03 request.h:78   (tid=8459455488): Request: obj_id=0, obj_size=1, ttl=-1, op=invalid
[INFO]  08-08-2024 12:59:03 request.h:78   (tid=8459455488): Request: obj_id=0, obj_size=1, ttl=-1, op=invalid
[INFO]  08-08-2024 12:59:03 request.h:78   (tid=8459455488): Request: obj_id=0, obj_size=1, ttl=-1, op=invalid
[INFO]  08-08-2024 12:59:03 request.h:78   (tid=8459455488): Request: obj_id=0, obj_size=1, ttl=-1, op=invalid
[INFO]  08-08-2024 12:59:03 request.h:78   (tid=8459455488): Request: obj_id=0, obj_size=1, ttl=-1, op=invalid
[INFO]  08-08-2024 12:59:03 request.h:78   (tid=8459455488): Request: obj_id=0, obj_size=1, ttl=-1, op=invalid
[INFO]  08-08-2024 12:59:03 request.h:78   (tid=8459455488): Request: obj_id=0, obj_size=1, ttl=-1, op=invalid
../data/twitter_cluster52.csv LRU cache size     1GiB,          1000000 req, miss ratio 0.0000, throughput 2.29 MQPS

Users will know right away if there's an issue with reading.

[xiaguan]

Thanks for the suggestion! I've made the updates to my PR.

[1a1a11a]

Great work! You may want to add this to doc :)

[1a1a11a]

Thank you!