feat: beautify the source maps

[smallp]

Description

Move source maps to source-maps://.

Additional context

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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.

[sapphi-red]

Could you add the same logic here for css sourcemaps?

vite/packages/vite/src/node/plugins/css.ts

Lines 353 to 355 in c86329b

	const sourcemap = this.getCombinedSourcemap()
	await injectSourcesContent(sourcemap, cleanUrl(id), config.logger)
	return getCodeWithSourcemap('css', content, sourcemap)

[smallp]

@sapphi-red
I don't believe we need to do that.
All requests would call transformRequest where I add namespace here. So we don't have to add it again.

[sapphi-red]

transformRequest won't be called for css dev sourcemaps because the source maps for them are inlined.

[smallp]

Got it. Done.

[smallp]

@sapphi-red Rebased. And who can review it? It is months.