Add a first version of a library enabling the reuse of components

This is the start of a library development where a user should be able to save specific AF3 elements (currently just components) in a general library and from then on the user should be able to reuse these elements in new/other projects. The feature can be enhanced by adding tracing/linking to get update of reused elements when their original element is changed/updated, or by expanding the supported element types, but for the moment only a basic/simple test version should be realized.

Feature description:

• open a AF3 project with at least one component
• select one component and let it be saved (probably right click with a new context line "Save for reuse")

Expected behavior:

• (only) the selected component is saved in a separate place aka library
• it is visible in a list with all other saved components inside the reuse library (maybe a new category in "Model Elements" below "Component Architecture")
• it can be inserted in any new AF3 project via drag and drop from this list

Actual behavoir:

• none: not yet possible/realized

Edit:

• The reuse library was already extended for requirements and data dictionary entries (in addition to components)