Fixed NodeId.CompareTo() null reference exception

[mrsuciu]

Proposed changes

Fixes the null reference exception

Related Issues

• Fixes NodeId.CompareTo(Object obj) throws if InnerNodeId is null #2262

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• Bugfix (non-breaking change which fixes an issue)
• Enhancement (non-breaking change which adds functionality)
• Test enhancement (non-breaking change to increase test coverage)
• Breaking change (fix or feature that would cause existing functionality to not work as expected, requires version increase of Nuget packages)
• Documentation Update (if none of the other choices apply)

Checklist

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Further comments

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[codecov]

Codecov Report

Merging #2263 (e7e657b) into master (cfb3ac4) will decrease coverage by 0.03%.
Report is 5 commits behind head on master.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #2263      +/-   ##
==========================================
- Coverage   58.95%   58.92%   -0.03%     
==========================================
  Files         330      330              
  Lines       63198    63244      +46     
==========================================
+ Hits        37257    37268      +11     
- Misses      25941    25976      +35     

Files Changed	Coverage Δ
Stack/Opc.Ua.Core/Types/BuiltIn/NodeId.cs	82.90% <100.00%> (+0.57%)	⬆️

... and 34 files with indirect coverage changes