Happy need an echo mock app to test ExchangeManager end-to-end

[yufengwangca]

Problem

Right now, we don't have an end-to-end testing for ExchangeManager/CRMP in CHIP, we are not able to detect the regression or break on the protocol level. After Echo protocol landed, we can add the test mock app to serve this purpose.

Proposed Solution

Add echo client/server mock apps for Happy automation testing

@andy31415 @rwalker-apple @erjiaqing @yunhanw-google

[issue-label-bot]

Issue-Label Bot is automatically applying the label feature_request to this issue, with a confidence of 0.85. Please mark this comment with 👍 or 👎 to give our bot feedback!

Links: app homepage, dashboard and code for this bot.