chore: migrate sample event column to text for reporting

[itsmihir]

Description

Recently, we migrated the jobsDB payload column to the text type; however, in the reports and error_detail_reports tables, we still use the jsonb type to store sample_event. This has led to instances where Postgres failed to cast sample_event from string to jsonb due to special characters, resulting in processor panics.
This PR migrates the sample_event column in these tables from jsonb to text to ensure consistency and prevent such failures.

Linear Ticket

Resolves OBS-776

Security

• The code changed/added as part of this pull request won't create any security issues with how the software is being used.

[codecov]

Codecov Report

Attention: Patch coverage is 80.00000% with 6 lines in your changes missing coverage. Please review.

Project coverage is 75.02%. Comparing base (734e759) to head (6230d61).

Files with missing lines	Patch %	Lines
processor/processor.go	64.28%	5 Missing ⚠️
router/batchrouter/handle.go	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5503      +/-   ##
==========================================
- Coverage   75.04%   75.02%   -0.03%     
==========================================
  Files         460      460              
  Lines       63548    63548              
==========================================
- Hits        47692    47675      -17     
- Misses      13204    13219      +15     
- Partials     2652     2654       +2     

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