Fix an issue where the same hash was generated when different variables were exported under the same name

[lukastaegert]

This PR contains:

• bugfix
• feature
• refactor
• documentation
• other

Are tests included?

• yes (bugfixes and features will not be merged without tests)
• no

Breaking Changes?

• yes (breaking changes will not be merged unless absolutely necessary)
• no

List any relevant issue numbers:

Description

The previous hashing algorithm only took generated export names in account which caused hash conflicts if different variables were exported using the same names via e.g. export {foo} vs. export {bar as foo}. The new algorithm now takes three things into account:

• the exported name
• the original variable name in the source
• the module this variable belongs to (as only in this context, the top level variable name is unique);