Update mrc_get_parameter to respond to mrcOnMove and mrcOnAncestorMove (#269)

* Reformatted mrc_class_method_def.ts.

* In mrc_class_method_def.ts:
Changed type Parameter to interface Parameter and export it.
Added method mrcGetParameterNames.

In mrc_event.ts:
Import Parameter from mrc_class_method_def.ts.
Fixed comment for mrcOnMove.

In mrc_event_handler.ts:
Import Parameter from mrc_class_method_def.ts.
Added method mrcGetParameterNames.

In mrc_get_parameter.ts:
Added constants FIELD_PARAMETER_NAME and WARNING_ID_GET_PARAMETER.
Removed parameterType from GET_PARAMETER_BLOCK.
Added mrcParameterType and mrcHasWarning to GetParameterMixin.
Replaced onBlockChanged with mrcOnMove, mrcOnAncestorMove, and checkBlockPlacement.
Updated checkBlockPlacement to call mrcGetParameterNames on the root block if it is a
mrc_class_method_def or mrc_event_handler block.

In editor.ts:
Added code to call mrcOnAncestorMove for all descendants of the block that was moved.

Author: lizlooney