Better instructions in the Wechat login Continue screen

## Context
There are 2 steps in the wechat login flow,
1. Tap to open the WeChat App
- Approve the login from the wechat app
2. Go back to the Authgear screen in the client app
- Tap to "Continue" the login (to retrieve the authorization result from wechat)
3. Completed and redirected to the client


## Problem

The user may not know the second screen is different from the 1st one because they look very similar and hard to understand the flow, and the user may tap "Cancel" and quit the authentication flow

## Solution

Make the 2nd screen more distinctive and offer more context

Title:
zh-Hant-HK/TW :`繼續 WeChat 帳戶登入`
zh-Hans-CN :`繼續微訊帳戶登入`
en: `Continue WeChat Login`

Paragraph:
zh-Hant-HK/TW :`從WeChat確認登入回來後，按以下按鈕繼續`
zh-Hans-CN :`從微訊確認登入回來後，按以下按鈕繼續`
en: `After returning from WeChat, press the following button to continue`

Button:
zh-Hant-HK/TW :`繼續`
zh-Hans-CN :`繼續`
en: `Continue`

Secondary button:
zh-Hant-HK/TW : `重啓WeChat App登入`
zh-Hans-CN: `重啓微訊應用登入`
en: `Re-authorize the login in WeChat`

Start at the WeChat login flow's second, Continue screen and find the localized title, paragraph, Continue button, and re-authorization button. Update the zh-Hant-HK/TW, zh-Hans-CN, and English wording so this screen is distinct from the first step, then verify that returning from WeChat offers the new actions and preserves the login flow.

Written by the indexing model from the issue text.