Avoid overwrite of endpoint description with invalid endpoint description on client session.

Proposed changes

Avoid overwrite of endpoint description with endpoint description of other endpoint than the one used in current session, in case server exposes multiple endpoints on different ports.

Types of changes

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[x] 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

Put an x in the boxes that apply. You can also fill these out after creating the PR. If you're unsure about any of them, don't hesitate to ask. We're here to help! This is simply a reminder of what we are going to look for before merging your code.

[x] I have read the CONTRIBUTING doc.
[x] I have signed the CLA.
[x] 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.

Further comments

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Codecov Report

Attention: 8 lines in your changes are missing coverage. Please review.

Comparison is base (deb3391) 52.98% compared to head (c97fcc0) 53.82%. Report is 4 commits behind head on master.

Files	Patch %	Lines
Libraries/Opc.Ua.Client/Session.cs	69.23%	4 Missing and 4 partials :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #2506 +/- ## ========================================== + Coverage 52.98% 53.82% +0.83% ========================================== Files 319 334 +15 Lines 62985 64435 +1450 Branches 12927 13227 +300 ========================================== + Hits 33375 34679 +1304 - Misses 25920 25996 +76 - Partials 3690 3760 +70 ```

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OPCFoundation / UA-.NETStandard