UInt8Array toBase64 and fromBase64 support

[cmackenzie1]

Would be great to add the following APIs.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array/toBase64
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array/fromBase64

Currently, as a workaround I am using NodeJS Buffer.from(payload, 'base64') and Buffer.from(message.data).toString('base64')

describe("base64", () => {
    it('works?', () => {
        const buf = new TextEncoder().encode('Hello World')
        expect(buf.toBase64()).toEqual("SGVsbG8gV29ybGQ=")
        expect(Uint8Array.fromBase64("SGVsbG8gV29ybGQ=")).toEqual('Hello World')
    })
})

[jasnell]

We will get these automatically when v8 makes them available. I'm not currently aware what their timeline for these looks like.

[cmackenzie1]

Thanks, @jasnell. I figured that would be the cause. I did some searching and I think this is the corresponding v8 issue tracking its implementation. https://issues.chromium.org/issues/42204568