[CLI] --dry command to print out matched files and dest paths

It can be quite difficult to discern & debug bsconfig files arrays that are not working (when you expect them to work).

• The only way to identify valid "pkg:/ paths produced by a bsconfig is to generate a build or experiment with auto-complete suggestions.
• Neither option is viable if the bsc language extension or bsconfig file(s) are throwing errors

Proposed solution:

• a command or flag (such as --dry or --files that prints out the list of
  • (1) the src files that are matched
  • (2) the resulting dest pkg:/ file paths
• this command should not fail due to validation errors unless the error prevents the successful parsing of the files bsconfig data

note:
i'm gonna take a stab at implementing this today/tomorrow

Start at the CLI entry point that parses bsconfig files and follow the existing handling of the files array, including how matched sources become pkg:/ destinations. Run the proposed dry-run command against a bsconfig with valid and invalid settings; done means it prints both matched source files and destination paths while only failing when the files data cannot be parsed.