add separate error log file for mpp_error

[rem1776]

Description
Adds a separate log file called "warnfile.<root pe num>.out" that only holds output from mpp_error calls along with a unit test.

Fixes #1475

How Has This Been Tested?
tested with oneapi 2024.01 on the and box

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules
• New check tests, if applicable, are included
• make distcheck passes

[bensonr]

lgtm