fix(plugin-react): support import namespace in parseReactAlias

[aleclarson]

Description

When @vitejs/plugin-react parses node_modules, it looks for a React import. What it doesn't look for, however, is…

import * as React from "react"

…even though it should. This PR adds that.

To be clear, this only affects parsing of node_modules. This syntax is already supported for project files.

Additional context

I've also made the regexes less strict about whitespace, and I added some unit tests.

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the Commit Convention.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.