[Suggestion] Enhance the LSP features to include support for File Master Plus batch commands

[zeibura]

I'd like to propose an update to this extension which adds support for File Master Plus batch commands and keywords. This would integrate JCL Language Support with two Broadcom products: File Master Plus and File Master Plus for IMS. Both products support batch processing in JCLs and adding support to JCL Language Support would enable users to do this work more easily in an IDE interface.

My proposed solution would be to translate the batch commands and keywords sections of the FMP documentation into a parser file for use in this extension so that syntax check and autocomplete features are also enabled for FMP batch commands and keywords. (I have written parsers before for COBOL Language Support so I can help with this.) I am not entirely sure how the syntax check part would work considering it seems to be done through the Zowe CLI plug-in rather than through the extension itself.

The syntax of FMP and FMIMS batch commands and keywords is documented in this section of the FMP documentation: Using Batch