Plugin update: Image Assembler

[nishaq503]

This PR updates the Image assembler plugin to the new plugin standards.

It includes work from:

• Antoine (@agerardin) to update the plugin to use filepattern2 and preadator
• me to update the plugin with new pre-commit hooks and some code refactoring.

TODO:

• One of the tests hangs. I have asked for input from Antoine on this.
• Optionally, we want to run tests on images from MIST.
• After passing reviews, we need to bump the version number.
• Close the old PR.
• After merging the docs PR on preadator, we need to update the dependency in pyproject.toml.

[sweep-ai-deprecated]

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• Apply: Leftover TODOs in the code should be handled.
• Apply: All new business logic should have corresponding unit tests in the tests/ directory.
• Apply: Any clearly inefficient or repeated code should be optimized or refactored.