Remove value_node_db batch

[StephenButtolph]

Why this should be merged

We currently allocate a valueNodeBatch.ops map for no reason. This removes this unused map.

Seems to provide as much as a ~22% speedup (using memdb).

Before:

BenchmarkCommitView/apply_and_commit_changes-12         	     561	   2142773 ns/op	  583440 B/op	    4920 allocs/op

After:

BenchmarkCommitView/apply_and_commit_changes-12         	     685	   1673874 ns/op	  438132 B/op	    4904 allocs/op

How this works

Removes valueNodeBatch and uses the baseDB.Batch instead.

How this was tested

• Added benchmark
• CI