Refactor:Move the relaxation part of the ucell function

[A-006]

Unit Tests and/or Case Tests for my changes

• Modify the funciton of remake_cell,setup_cell_after_vc in unittest.
• The unit test of setup_cell_after_vc is not check in the before,add the result for this func.

What's changed?

• move function of remake_cell,setup_cell_after_vc in ucell to update_ucell.cpp
• The remake_cell function is not run in the relax_test.cpp,add the test for this func.