refactor: Replace deprecated substr with substring

[cbaker6]

Pull Request

• Report security issues confidentially.
• Any contribution is under this license.
• Link this pull request to an issue.

Issue

substr() has been deprecated.

Closes: #8645

Approach

• Use substring() instead and fix issues where needed
• Refactor rotateEncryptionKey() in GridFSBucketAdapter.js to use async/await since already refactoring substr() in the same file

Tasks

• Ensure tests pass

[parse-github-assistant]

Thanks for opening this pull request!

[codecov]

Codecov Report

Patch coverage: 95.00% and project coverage change: +0.03 🎉

Comparison is base (45301a6) 94.41% compared to head (1e8ce50) 94.44%.

❗ Current head 1e8ce50 differs from pull request most recent head f8f095b. Consider uploading reports for the commit f8f095b to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##            alpha    #8644      +/-   ##
==========================================
+ Coverage   94.41%   94.44%   +0.03%     
==========================================
  Files         184      184              
  Lines       14613    14604       -9     
==========================================
- Hits        13797    13793       -4     
+ Misses        816      811       -5     

Impacted Files	Coverage Δ
...dapters/Storage/Postgres/PostgresStorageAdapter.js	95.74% <83.33%> (ø)
src/Adapters/Files/GridFSBucketAdapter.js	96.96% <100.00%> (+2.64%)	⬆️
src/Config.js	91.27% <100.00%> (ø)

... and 1 file with indirect coverage changes

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.

[cbaker6]

@mtrezza @dblythy this is ready for review

[mtrezza]

Looks good

[parseplatformorg]

🎉 This change has been released in version 6.3.0-alpha.2

[parseplatformorg]

🎉 This change has been released in version 6.4.0-beta.1

[parseplatformorg]

🎉 This change has been released in version 6.4.0-alpha.1

[parseplatformorg]

🎉 This change has been released in version 6.4.0