[rollup-plugin-import-meta-assets] Fix resolving and respect `external` rollup option

[CGNonofr]

The plugin currently doesn't support:

• custom resolvers (it just resolves the path with node path tool)
• external configuration (everything is considered as internal and bundled)

That PR implements that

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Latest commit: f7843763bef3983c3f7644f366f639d330167958

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[bashmish]

can you please add unit tests?

[CGNonofr]

can you please add unit tests?

done! fixed the current test and added a new test

[CGNonofr]

Btw, I'm not sure about the "ignore if it's a directory" feature, I don't really see the point of it, and the user can now explicitely ignore it by setting it as external

[CGNonofr]

Just fixed the tests for windows

[CGNonofr]

up?