[Server] Fix: Return full CertificateChain after Certificate Update

[romanett]

Proposed changes

Fix the CertificateTypesProvider to also return the correct chain after a CertificateUpdate occured.

Types of changes

• 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

• I have read the CONTRIBUTING doc.
• I have signed the CLA.
• I ran tests locally with my changes, all passed.
• I fixed all failing tests in the CI pipelines.
• I fixed all introduced issues with CodeQL and LGTM.
• I have added tests that prove my fix is effective or that my feature works and increased code coverage.
• I have added necessary documentation (if appropriate).
• Any dependent changes have been merged and published in downstream modules.

[codecov]

Codecov Report

Attention: Patch coverage is 82.35294% with 3 lines in your changes missing coverage. Please review.

Project coverage is 55.40%. Comparing base (0777bbd) to head (49dd612).
Report is 11 commits behind head on master.

Files with missing lines	Patch %	Lines
...a.Server/Configuration/ConfigurationNodeManager.cs	77.77%	2 Missing ⚠️
Stack/Opc.Ua.Core/Stack/Server/ServerBase.cs	87.50%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2861      +/-   ##
==========================================
- Coverage   55.43%   55.40%   -0.04%     
==========================================
  Files         352      352              
  Lines       67602    67615      +13     
  Branches    13849    13851       +2     
==========================================
- Hits        37477    37462      -15     
- Misses      26021    26050      +29     
+ Partials     4104     4103       -1     

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