[production/RRFS.v1] adds bucket code for 15 minute QPF, cleans up legacy makefiles

[MatthewPyle-NOAA]

DESCRIPTION OF CHANGES:

Adds new rrfs_bucket.fd code. It probably isn't in final form, but want to get it established within rrfs_utl. Also cleaned out some legacy makefiles from the pre-cmake build system for the bufrsnd codes.

TESTS CONDUCTED:

Confirmed that it all builds, and confirmed that the rrfs_bucket executable built from this rrfs_utl could run a simple offline test script of the bucket processing.

DEPENDENCIES:

DOCUMENTATION:

ISSUE (optional):

Partially resolves this issue.

CONTRIBUTORS (optional):

[christopherwharrop-noaa]

Thank you for this update and especially for removing the obsolete makefiles. My only request is in regards to the bucket_diff.f file being added. The coding style does not incorporate proper indentation for conditionals and loops and is very inconsistent throughout. As a result the code is very hard to read and understand.
Since this is a new addition, it would be nice to have that cleaned up at the start. Could you please add consistent indentation for that new code?

[MatthewPyle-NOAA]

@christopherwharrop-noaa Good suggestion - did some formatting cleanup. Let me know if that wasn't enough.

[christopherwharrop-noaa]

Thank you very much for fixing the indentation. That is a huge improvement that makes the code a lot easier to look at.

[MatthewPyle-NOAA]

Will have another commit for this one - my updated code had an error preventing it from compiling. Once I confirm that this problem is resolved, will push another change.