fix: TypeError when listing data sets after opening one w/ encoding

[traeok]

Proposed changes

Resolves #3347

How to test

1. Set a valid search pattern on a profile in your Data Sets tree.
2. Open one of the datasets in the list with a specific encoding - right-click -> "Open with Encoding"
3. Select an encoding to open the data set in an editor tab.
4. Once opened, set a search pattern on your profile that returns no results (ex: PROWOBUF).
5. Then, set the same search pattern used in step 1.
6. Once the search is finished, the data sets are listed without any errors.

Following the same steps when using the main branch or 3.0.3 VSIX results in a TypeError.

Release Notes

Milestone: 3.1.0 (or a 3.0.4 if needed?)

Changelog:

• Fixed an issue where listing data sets resulted in an error after opening a data set with an encoding. #3347

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Enhancement (non-breaking change which adds or improves functionality)
• Breaking change (a change that would cause existing functionality to not work as expected)
• Documentation (Markdown, README updates)
• Other (please specify above in "Proposed changes" section)

Checklist

General

• I have read the CONTRIBUTOR GUIDANCE wiki
• All PR dependencies have been merged and published (if applicable)
• A GIF or screenshot is included in the PR for visual changes
• The pre-publish command has been executed:
  • v2 and below: yarn workspace vscode-extension-for-zowe vscode:prepublish
  • v3: pnpm --filter vscode-extension-for-zowe vscode:prepublish

Code coverage

• There is coverage for the code that I have added
• I have added new test cases and they are passing
• I have manually tested the changes

Deployment

• I have added developer documentation (if applicable)
• Documentation should be added to Zowe Docs
  • If you're an outside contributor, please post in the #zowe-doc Slack channel to coordinate documentation.
  • Otherwise, please check with the rest of the squad about any needed documentation before merging.
• These changes may need ported to the appropriate branches (list here):

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.15%. Comparing base (7f253c1) to head (2076491).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3348      +/-   ##
==========================================
+ Coverage   93.13%   93.15%   +0.01%     
==========================================
  Files         117      117              
  Lines       12244    12245       +1     
  Branches     2810     2768      -42     
==========================================
+ Hits        11404    11407       +3     
+ Misses        839      837       -2     
  Partials        1        1              

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[adam-wolfe]

LGTM, will let others review.

[zFernand0]

Had a hard time reproducing since the error doesn't seen to come up for PDS members (only of PS datasets)

After seeing the GIF in the issue, I realized my mistake in testing 😋

LGTM! 😋