fix: support vite client in safari 13

[bluwy]

Description

Fix #9190 (comment)

Our baseline supports Safari 13, which doesn't support optional chaining. Since vite/client is served unbundled, we should also support Safari 13. Changing the typescript compile target to es2019 from es2020 (declared in tsconfig.base.json), transpile the optional chaining usage.

cc @Amareis

Additional context

Diff of new vs old client.mjs:

bjorn@Bjorns-MacBook-Pro vite % diff client.mjs client2.mjs
122d121
<         var _a;
135c134
<         const [file] = (((_a = err.loc) === null || _a === void 0 ? void 0 : _a.file) || err.id || 'unknown file').split(`?`);
---
>         const [file] = (err.loc?.file || err.id || 'unknown file').split(`?`);
179,180c178
<         var _a;
<         (_a = this.parentNode) === null || _a === void 0 ? void 0 : _a.removeChild(this);
---
>         this.parentNode?.removeChild(this);

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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[Amareis]

Yep, that's really needed for testing on old iPhones!

(But i still think that support for safari 12 will be much better, since it has no real differences with 13, but still have some users)