Implement tasking system

[computablee]

This PR aims to implement a tasking system into DotMP. It won't be as robust as OpenMP, but my hope is that it can be expanded upon in the future. This PR includes:

• Modifications to DotMP.Parallel.Sections and the removal of DotMP.Parallel.Section
• An implementation of DotMP.Parallel.Task
• An implementation of DotMP.Parallel.Taskwait
• An implementation of DotMP.Parallel.Taskloop
• An implementation of DotMP.Parallel.ParallelMaster
• An implementation of DotMP.Parallel.MasterTaskloop
• An implementation of DotMP.Parallel.ParallelMasterTaskloop
• Basic dependency chains
• Unit tests for everything
• Updated documentation for everything

All in accordance with #31. Opening as a draft for now, will complete when everything is finished.

[computablee]

Most of the work is done, but currently there are some major performance issues after adding dependencies. Keeping track of dependencies is proving to be an expensive operation, so I will need to rethink the DAG class.