Fix errors when editing Tree due to missing insPrevID in CRDTTree

[humdrum]

What this PR does / why we need it:

• Fix errors when editing Tree due to missing insPrevID in CRDTTree yorkie-js-sdk#756

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

Additional documentation:

Checklist:

• Added relevant tests or not required
• Didn't break anything

[codecov]

Codecov Report

Attention: Patch coverage is 1.12994% with 175 lines in your changes are missing coverage. Please review.

Project coverage is 41.96%. Comparing base (2dee076) to head (64c116e).

Files	Patch %	Lines
Tests/Integration/TreeIntegrationTests.swift	0.00%	175 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #153      +/-   ##
==========================================
- Coverage   42.25%   41.96%   -0.30%     
==========================================
  Files         104      104              
  Lines       24389    24566     +177     
==========================================
+ Hits        10306    10308       +2     
- Misses      14083    14258     +175     

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