Updated Input and Output components to use the most recent interface design

Several test run outputs can now be merged and output when requested, to
better support running the same test input several times in different
data populations.
Identifiers are now passed to SQLQuery's constructor. Also InternalParam is initialized to avoid crashes when disabling parameter reads
Refactored internal parameter handling. Internal parameters are now read and written from input/output components.

Parameter loading and storing must now be done in IInputHandler or
IOutputHandler components, allowing internal parameters to be ignored,
depending on the component implementations. IInternalParameterHandlers
will now only function as an (almost) stateless input/output tool, to be
used by input/output components