Resolve "graph of deserialized group nodes does not contain the nodes of group"

Closes #89

See merge request !41

Update unit tests accordingly.  Groups seem to work now.

still producing port mapping bugs...

Resolve "Group: Add analysis unit test"

Closes #80

See merge request !40

Resolve "Reference node: add analysis unit test"

Closes #81

See merge request !37

Resolve "show CLI intro only when neither help not version flag is used"

Closes #87

See merge request !38

Update & extend unit tests accordingly.

Resolve "clippy warnings in CLI merge"

Closes #86

See merge request !36

Resolve "CLI: Add version info also in --version dialog"

Closes #69

See merge request !32

# Conflicts:
#   Cargo.toml

Resolve "Reference nodes are not correctly restored from file"

Closes #62

See merge request !35

Further testing needed.

Add Uuid to OpticRef

Closes #63

See merge request !34