fix(channel-web): fix switching user language

[laurentlp]

Description

This PR adds the mapping between visitorId and userId logic inside the switchLanguage builtin action. This fixes changing the user language and updating the channel-web UI accordingly.

Another solution I tough about was to handle this logic inside the forVisitor function (packages/bp/src/core/realtime/payload-sdk-impl.ts). But I think it would be overkill to have to make sure the user sends a visitorId and if not, to check if the userId corresponds to some visitorId and then fetch this value.

We could also expose a getVisitorId in the SDK but considering that web_user_map is a temporary table and will be deprecated in the future, we might not want to go that route.

Please, let me know if you have a better idea of what we could do here!

Fixes botpress/v12#1541
Closes DEV-1984

Type of change

• Bug fix (non-breaking change which fixes an issue)

How has this been tested?

Use the builtin/switchLanguage function and set the language to fr and then en. You will see the UI if the webchat change from English to French and then back to English.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code

[linear]

DEV-1984 [BUG] switchLanguage action not working (botpress/borpress botpress/v12#1541)

Describe the bug
Due to the messaging split, bp.RealTimePayload.forVisitor(event.taget... is no longer working

To Reproduce
Steps to reproduce the behavior:

1. Use the action switchLanguage from the builtin module, it will not work correctly

A room id is now expected, not as same as event.target

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
If applicable, add screenshots to help explain your problem.

Environment (please complete the following information):

• OS: Windows
• Browser Chrome
• Botpress Version 12.26.6
• NodeJS 12.18.1

botpress/borpress botpress/v12#1541 by @ davidvitora

[samuelmasse]

LGTM