feat: Cron job to mark event invoices as due

[mrsaicharan1]

Fixes #6165

Short description of what this resolves:

As soon as the event invoice is 30 days old, the status should change to due.

Changes proposed in this pull request:

• Scheduled a task for event invoice due marking

Checklist

• I have read the Contribution & Best practices Guide and my PR follows them.
• My branch is up-to-date with the Upstream development branch.
• The unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

• All the functions created/modified in this PR contain relevant docstrings.

[codecov]

Codecov Report

Merging #6166 into development will decrease coverage by 0.01%.
The diff coverage is 33.33%.

@@               Coverage Diff               @@
##           development    #6166      +/-   ##
===============================================
- Coverage         66.2%   66.18%   -0.02%     
===============================================
  Files              288      288              
  Lines            14454    14460       +6     
===============================================
+ Hits              9569     9571       +2     
- Misses            4885     4889       +4

Impacted Files	Coverage Δ
app/__init__.py	87.07% <100%> (+0.07%)	⬆️
app/api/helpers/scheduled_jobs.py	21.6% <20%> (-0.07%)	⬇️

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