TG-967:Fix weekly report date column issue

[RevathiKotla]

This includes fixes for

• Removing the columns in the report headers order if not specified in the report config while generating and merging new date to report csv
• Change the Date column to first of the order in header
• Handle the json exponential columns-metric labels null pointer issue

Type of change

Please choose appropriate options.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes in the below checkboxes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Added test cases and verified few running reports in loadtest

Test Configuration:

• Software versions:
• Hardware versions:

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
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!

0 Bugs
0 Vulnerabilities
0 Security Hotspots
1 Code Smell

100.0% Coverage
0.0% Duplication