Modify Operation classes to store a wstring instead of TaskId
Cast TaskId to wstring before instantiating Operation objects
Fix tests to adhere to the changes
Document Operation classes
Refactor IOperation to Operation
Operation classes now requires another parameter branchName, name of branch to modify
Fixes to Operation instantiation to adhere to the changes
Implement a separate parse method that does not throw an exception.
Give a non throwing overload for the query parser also.
Fix data type mismatches for filtering values.

Fixes #243.
Improve code coverage.
Undo stores last filter and comparator
And GetTask will store them
Undo refreshes task list
lint fix
Liiiiiiiiiiiiiints.
Fix unit tests to follow the changes
Operation classes' run method receives xml_document instead of xml_node
Modify run implementation to seek the branch to be modified
Lint, and remove unnecessary includes in Operation classes