Fix #142 by changing includeTags filtering and restoring collection snapshots

[kirides]

fixes #142 by changing includeTags filtering and restoring collection snapshots.

exclusion is now defined in a single statement, instead of a loop, to reduce likelyhood of failures.

Fixes improper use of collection enumeration and mutation while doing so.
We may not use code like the following, as that may either crash or produce UB.

foreach (var x in collection.Where(x....))
{
    // NOT OK
    collection.Remove(y);
}

instead, every mutating operation on a collection should enumerate on a snapshot

foreach (var x in collection.Where(x....).ToArray())
{
    // OK
    collection.Remove(y);
}

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
1 Code Smell

No Coverage information
0.0% Duplication

[codecov]

Codecov Report

Merging #143 (6311a60) into main (38092e9) will decrease coverage by 0.09%.
The diff coverage is 90.00%.

@@            Coverage Diff             @@
##             main     #143      +/-   ##
==========================================
- Coverage   98.55%   98.47%   -0.09%     
==========================================
  Files          37       37              
  Lines        1176     1178       +2     
==========================================
+ Hits         1159     1160       +1     
  Misses          6        6              
- Partials       11       12       +1     

Flag	Coverage Δ
unittests	98.47% <90.00%> (-0.09%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files Changed	Coverage Δ
src/Refitter.Core/RefitGenerator.cs	99.31% <87.50%> (-0.69%)	⬇️
src/Refitter.Tests/Examples/FilterByTagsTests.cs	100.00% <100.00%> (ø)

[christianhelle]

Looks good to me