Graphical editor creates unneeded with statements.

[philip-alldredge]

When the text editor is open, setting the extended classifier graphically results in with statements being created regardless of the package. This results in duplicate with statements and with statements which reference the current package.

This is caused by multiple implementations of the logic to import a package if needed. AadlImportsUtil contains a working implementation and AadlHelper.ensurePackageIsImported() contains similar logic but compares packages by reference instead of by name. Need to cleanup. Both methods should share logic and be located in the same class.