CLI enhancements

[bladyjoker]

DONE

• Positional arguments introduces
• lbf receives a list of .lbf files that are eventually passed to lbg and these indicate WHICH codegen for
• lbg receives a list of module name to codegen
• Error reporting and UX workflows design&impl

Usage: lbf build [-i|--import-path FILEPATH] [-c|--compiler FILEPATH] 
                 [-g|--gen FILEPATH] --gen-dir FILEPATH [--gen-opt ARGUMENT] 
                 [-d|--debug] [-w|--work-dir FILEPATH] [.lbf SCHEMA]...

  Build LambdaBuffers .lbf schemas

Available options:
  -i,--import-path FILEPATH
                           Directory to look for LambdaBuffer Module source
                           files (.lbf)
  -c,--compiler FILEPATH   LambdaBuffers Compiler location (if none is set the
                           LB_COMPILER environment variable is used)
  -g,--gen FILEPATH        LambdaBuffers Codegen location (if none is set the
                           LB_CODEGEN environment variable is used)
  --gen-dir FILEPATH       Directory where the Codegen will store any output
                           produced from the LambdaBuffers schema
  --gen-opt ARGUMENT       Additional options to provide to the Codegen module
  -d,--debug               Run in debug mode
  -w,--work-dir FILEPATH   Working directory used to communicate with the
                           Compiler and Codegen components
  [.lbf SCHEMA]...         .lbf schemas to build
  -h,--help                Show this help text

$ lbg gen-haskell
Usage: lbg gen-haskell [-c|--config FILEPATH] (-i|--input FILEPATH) 
                       [-o|--output FILEPATH] (-g|--gen-dir FILEPATH) 
                       [-d|--debug] [module name]...

  Generate Haskell code from a compiled LambdaBuffers schema

Available options:
  -c,--config FILEPATH     Configuration file for the Haskell codegen module
  -i,--input FILEPATH      Compiled LambdaBuffers schema to generate code for
  -o,--output FILEPATH     Codegen output that can be used to inspect Codegen
                           errors
  -g,--gen-dir FILEPATH    Directory to print generation output to
  -d,--debug               Run in debug mode
  [module name]...         Modules to generate code for
  -h,--help                Show this help text