and refactore this function for better readability

and refactoring this function for better readability

Remove them from LevelGridBuilder

fixes pipeline #7586

For communication after interpolation fine to coarse

Find all send and recv indices which also are interface cells fine to coarse, coarse (iCellFCC).
Move them to the front of the vector of send and recv indices. Return their number as well.

instead of bc nodes

bulkOnly --> split domain

Thh new behaviour can turned off by passing false for the "onlyBulk" bool