Implement last cache optimize for query like select last(s1), last(s1, time), last(s2), last(s2, time)

[Wei-hao-Li]

Last Cache hit condition:

1. Select items are all made up of last or last_by;
2. For last_by, the first argument category type can be tag, attribute or time, the second can only be measurement.

Example:
Schema of table1

Hit cases:
select last(s1),last(device),last(time) from table1;
select last(s1),last_by(time,s1),last_by(device,s1) from table1
Miss cases:
select last(s1),last_by(s1,time) from table1;
select last(s1),last_by(s2,s1) from table1

Performance Test
Data generation：disable out_of_order write，1000 device * 50 sensor，client_number=10，loop=100，batch_size=100，disable all compaction

[JackieTien97]

Add some perf experiment results and current last cache hit condition in pr descriptions

[JackieTien97]

Add IT case:

          // insert into
          // delete from table1 where time >= 1;
          // select last(time), last(s1) from table1;
          // select last(time), last(s1) from table1;