- Renamed to PostprocessingAlgorithm.

- Accidentally renamed usages of DataProcessorCommandAdapter to
CommandAdapter rather than QtCommandAdapter. This commit fixes that.

- Added namespace to cpp files.
- Fixed some related compile errors due to forward declaration
placement.
- Fixed some mistyped namespaces in header files.

- Added DataProcessor as namespace for most headers in the
DataProcessorUI folder.
- Renamed some usages of AbstractDataProcessorTreeModel.

- This commit starts to replace occurenced of std::string, std::stringstream derivations and std::vector<std::string> with their Qt equivalents such as QString and QStringList.

- Modified the giveUserCritical method on the DataView mock to accept a QString.

- Modified QDataProcessorWidget::getUserCritical to accept QStrings rather than std::strings.
- Adjusted usages of this function accordingly.
- Extracted a function ReflDataProcessorPresenter::retrieveWorkspaceByName from parseUniform to
improve code readability.

Also made some changes to the one level model -i.e. model when no post-processing is defined

So clients using the widget do not need to implement them