feat(optimizer): improve the esbuild plugin converter to pass some properties of build result to onEnd

[lyzno1]

Description

Fixes #22356.

convertEsbuildPluginToRolldownPlugin() currently passes a throwing proxy to esbuild onEnd callbacks. That means normal esbuild-style code such as if (!result.metafile) return throws instead of seeing undefined when no metafile is available.

This PR passes a minimal valid esbuild.BuildResult instead, with empty errors and warnings and optional result fields set to undefined.

Tests

• pnpm exec vitest run packages/vite/src/node/__tests__/optimizer/pluginConverter.spec.ts
• pnpm exec vitest run packages/vite/src/node/__tests__/optimizer
• pnpm exec eslint --cache --concurrency auto packages/vite/src/node/optimizer/pluginConverter.ts packages/vite/src/node/__tests__/optimizer/pluginConverter.spec.ts
• pnpm exec oxfmt --check packages/vite/src/node/optimizer/pluginConverter.ts packages/vite/src/node/__tests__/optimizer/pluginConverter.spec.ts
• pnpm --filter vite typecheck

[sapphi-red]

I've kept errors and warnings to throw an error if accessed because if it's accessed it's commonly incompatible.