[core] revert abstract manifest entry code

Purpose

Abstract manifest entry is created as a loader for scan by projection push down. We can define a SimpleManifestEntry class when we trigger a manifest file scan with projection push down. But the main format we use for manifest file is "avro", which is a column oriented file format. We test it with projection push down, the result is not what we expected.

The promotion for avro is extraordinarily limited. About 10-20 percent performance improved. It is not worth making the project complex by defining a AbstractManifestEntry for such a little performance. So we decided to revert the related code, but we still remain the code about the memory limit.

In addition, we test orc file format as well. Found it has a big performance improvement about 100%. But it's unrealistic to shift to this in production environment. I will list the result of the test below:

Entries in one manifest file: 30000
Columns in one table: 30 (20 String Type)

For orc manifest file format:
Benchmark Mode Cnt Score Error Units
ReadWrite.testListPartition thrpt 4 66.479 ± 38.925 ops/s
ReadWrite.testListPartitionFull thrpt 4 34.702 ± 23.081 ops/s

For avro manifest file format:
Benchmark Mode Cnt Score Error Units
ReadWrite.testListPartition thrpt 4 14.758 ± 5.765 ops/s
ReadWrite.testListPartitionFull thrpt 4 12.903 ± 1.489 ops/s

Tests

API and Format

Documentation