Handling imports from sibling modules - #1027

PR Checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature (please, look at the "Scope of the project" section in the README.md file)
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• Other... Please describe:

What is the current behavior?

When a Python module imports another one in the same package, it can use the file name without the directory names. When Gazelle generate the targets, they are either in the same target or in sibling targets already depending on each other. However, Gazelle still tries to resolve them, even though no dependency resolution is needed

What is the new behavior?

Identify imports in sibling modules and ignore them.

Does this PR introduce a breaking change?

• Yes
• No

Other information