0024861: Extra solid is in the result of General Fuse Operation

0024861: Extra solid is in the result of General Fuse Operation

I. New features:
No new features.

II. Changes:
II.1. class BOPAlgo_ShellSplitter
   - statc function:
void RefineShell(TopoDS_Shell& theShell);
has been addded.
The function provides splitting connexity block of faces when the block begins with
the face that is intended to be internal.

II.2. class BOPAlgo_ShellSplitter
   - statc function:
Standard_Boolean IsClosedShell(const TopoDS_Shell& theShell);
has been modified to process empty shells.

II.3. class BOPAlgo_ShellSplitter
   - method:
void BOPAlgo_ShellSplitter::SplitBlock(BOPTools_ConnexityBlock& aCB);
has been modified to process connexity blocks of faces when the block
begins with the face that is intended to be internal [ II.1 ].

III. Modified entities:
packages:
BOPAlgo

Test case for issue CR24861