Create ZWE message analysis workflow

[MarkAckert]

This PR introduces an automated workflow designed to help us detect discrepancies in ZWE end-user messages through simple analysis of zwe sources and .errors files present in the zwe command subdirectories. If we want to further improve message consistency from this point, rather than making the automation more sophisticated we should probably discuss refactoring how messages are defined and accessed from ZWE itself.

The automation will identify the following issues with high confidence, causing the workflow to fail:

• Duplicate Message IDs defined in .errors files
• Messages which are used in ZWE but not defined in .errors files, and therefore not present in docs site.
• Message which are defined in .errors but never used in source code

The automation will identify with lower confidence:

• Messages whose content in source files does not match their definition in .errors files

All the issues are output in the workflow's log.