Make ForUtil#BLOCK_SIZE changeable

In LUCENE-10315, I tried to generate a ForUtil whose BLOCK_SIZE=512, I thought it could be simple since it looks like i only need to change the BLOCK_SIZE, but it turns out that there are a lot of values related to the BLOCK_SIZE but hard coded.

So this approach is trying to make all hard code value related to BLOCK_SIZE to be generated from the BLOCK_SIZE in case we need a different BLOCK_SIZE ForUtil somewhere else or want to change BLOCK_SIZE in postings in feature.

I tried to make the BLOCK_SIZE = 64 / 256 and all tests passed.