Resolve wrong path when import sub-path module with `browser` field

[ycjcl868]

Background:

esbuild/internal/resolver/package_json.go

Lines 185 to 191 in 105361d

	// Browserify allows a browser map entry of "./pkg" to override a package
	// path of "require('pkg')". This is weird, and arguably a bug. But we
	// replicate this bug for compatibility. However, Browserify only allows
	// this within the same package. It does not allow such an entry in a
	// parent package to override this in a child package. So this behavior
	// is disallowed if there is a "node_modules" folder in between the child
	// package and the parent package.

Bad Test Cases:

esbuild/internal/bundler/bundler_default_test.go

Lines 1392 to 1411 in e5e149d

	func TestSubImportModuleWithPkgBrowser(t *testing.T) {
	default_suite.expectBundled(t, bundled{
	files: map[string]string{
	"/entry.js": `
	import { v } from "pkg/sub";
	console.log(v);
	`,
	"/node_modules/pkg/package.json": `{ "browser": { "./sub": "./sub/index.js" } }`,
	"/node_modules/pkg/sub/index.js": `
	export { version as v } from "sub";
	`,
	"/node_modules/sub/index.js": `export const version = 123`,
	},
	entryPaths: []string{"/entry.js"},
	options: config.Options{
	Mode: config.ModeBundle,
	AbsOutputFile: "/out.js",
	},
	})
	}