Fix forward null issues (v2)

[awharn]

What It Does

Fixed several identified problems with possible null values in the tree and web views

How to Test

Review Checklist I certify that I have:

• [x] tested my changes
• [ ] added/updated automated tests
• [x] updated the changelog
• [x] followed the contribution guidelines

Additional Comments

[codecov-commenter]

Codecov Report

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

Project coverage is 93.28%. Comparing base (48cc278) to head (8d28bcc). Report is 2 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #121 +/- ## ======================================= Coverage 93.28% 93.28% ======================================= Files 74 74 Lines 760 760 Branches 94 93 -1 ======================================= Hits 709 709 Misses 51 51 ```

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[github-actions[bot]]

Release succeeded for the main branch. :tada:

The following packages have been published:

• npm: @zowe/cics-for-zowe-sdk@5.0.6
• npm: @zowe/cics-for-zowe-cli@5.0.6
• vsce: Zowe.cics-extension-for-zowe@2.3.6
• vsce: Zowe.cics-extension-for-zowe@2.3.6 (OVSX)

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