Small polygons with no features inside the regular splitted polygons

[manjitapandey]

Describe the bug
In some cases of splitting task using task splitting algorithm, the regular splitted polygon contains small polygons with no features inside.

To Reproduce
Steps to reproduce the behavior:

1. Go to 'fmtm'
2. Click on 'create project'
3. Apply task splitting algorithm.
4. See error

Expected behavior
In case there is any polygon or line or point which are counted as a task exist inside the polygon, that should be removed.

Screenshots

[spwoodcock]

Dup of #28

[Sujanadh]

I don't think its duplicate, #28 is related to smaller tasks with few numbers of features or without features. My PR only fixes those small tasks which donot have any features in it(considered as holes). I will be working on this issue onward.