port(ftp): Use `sha256` instead of `sha1`

[traeok]

Proposed changes

This is a port of the SHA256 change for the main branch.

Release Notes

Milestone:

Changelog:

Types of changes

What types of changes does your code introduce to Zowe Explorer? Put an x in the boxes that apply

• [x] Bugfix (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)
• [ ] Updates to Documentation or Tests (if none of the other choices apply)

Checklist

Put an x in the boxes that apply. You can also fill these out after creating the PR. If you're unsure about any of them, don't hesitate to ask. We're here to help! This checklist will be used as reference for both the contributor and the reviewer

• [x] I have read the CONTRIBUTOR GUIDANCE wiki
• [x] PR title follows Conventional Commits Guidelines
• [x] PR Description is included
• [ ] gif or screenshot is included if visual changes are made
• [x] yarn workspace vscode-extension-for-zowe vscode:prepublish has been executed
• [x] All checks have passed (DCO, Jenkins and Code Coverage)
• [ ] I have added unit test and it is passing
• [ ] I have added integration test and it is passing
• [x] There is coverage for the code that I have added
• [x] I have tested it manually and there are no regressions found

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
50.0% Duplication on New Code

See analysis details on SonarCloud

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 93.46%. Comparing base (8652863) to head (a47e236).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #2892 +/- ## ======================================= Coverage 93.46% 93.46% ======================================= Files 103 103 Lines 10763 10763 Branches 2346 2327 -19 ======================================= Hits 10060 10060 Misses 702 702 Partials 1 1 ```

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