feat: endpoint to fetch transaction status of an order via paytm

[shreyanshdwivedi]

Fixes #6401

Short description of what this resolves:

Implement route to get transaction status of the payment to verify if payment is actually made or not

Changes proposed in this pull request:

• adds a route to check the transaction status

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.

[shreyanshdwivedi]

This PR can be merged only after #6399 is merged.
The hound errors will automatically be resolved once the mentioned PR is merged

[codecov]

Codecov Report

Merging #6402 into development will decrease coverage by 0.09%.
The diff coverage is 5.88%.

@@              Coverage Diff              @@
##           development   #6402     +/-   ##
=============================================
- Coverage        64.49%   64.4%   -0.1%     
=============================================
  Files              288     288             
  Lines            15039   15056     +17     
=============================================
- Hits              9700    9697      -3     
- Misses            5339    5359     +20

Impacted Files	Coverage Δ
app/api/orders.py	26.25% <5.88%> (-0.91%)	⬇️
app/api/helpers/scheduled_jobs.py	20.93% <0%> (-3.11%)	⬇️

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[shreyanshdwivedi]

@uds5501 @mrsaicharan1 please review this

[shreyanshdwivedi]

@mrsaicharan1 please review

[mrsaicharan1]

Additionally, I've also created a method which serves as a helper to hit the endpoint instead of repeating code in each of the route's mapped functions. Please make use of it :)

open-event-server/app/api/helpers/payment.py

Line 345 in 003bf08

def hit_paytm_endpoint(url, head, body=None):

[shreyanshdwivedi]

@mrsaicharan1 I cannot use the helper hit_paytm_endpoint because the Transaction Status API doesn't ask us to segregate the paytmParams in head and body but your helper does so.
This API is different from others. Please take a look at https://developer.paytm.com/docs/transaction-status-api/

[shreyanshdwivedi]

@iamareebjamal please review