Review and externalize MCP server messages #32863
Description
Go through the MCP Server feature code and move every user-visible message into an nlsProps file so that it can be translated. This includes all log messages at info or above and all exception messages that users are expected to see.
We also need to add an explanation and user action for each message so that the user knows what it means and what to do about it. This information gets included in our documentation on pages like this: https://www.ibm.com/docs/en/was-liberty/nd?topic=messages-cwmcg
Messages must follow the Message Guidelines (internal link) and many will need to be rewritten and the corresponding tests updated.
The message prefix CWMCM has been reserved for the MCP feature. (CWMCP was already taken 😞 )
Messages must be reviewed for language and clarity by ID and L2. Usually a bot would request this automatically when a PR is made to integration, but because this is a feature branch we'll have to request a review manually.