Cannot export settings where it contains non-8bit chars

0. Settings -> Filtering
1. Enter 假的测试 into Wordfilter
2. Export

Uncaught DOMException: String contains an invalid character export_import.js:11:4
    exportData export_import.js:11
    backup settings_modal.js:124
    backup self-hosted:1115
    render/<.default</<.content</_cache[3]< settings_modal.vue:72
    withModifiers runtime-dom.esm-bundler.js:1466
    patchStopImmediatePropagation runtime-dom.esm-bundler.js:380
    callWithErrorHandling runtime-core.esm-bundler.js:155
    callWithAsyncErrorHandling runtime-core.esm-bundler.js:164
    callWithAsyncErrorHandling runtime-core.esm-bundler.js:174
    invoker runtime-dom.esm-bundler.js:366
    (Async: EventListener.handleEvent)

btoa does not work with non-ascii strings.

https://developer.mozilla.org/en-US/docs/Web/API/btoa#unicode_strings