NTLM token, Similarity filter update, Pattern for base64 filter update

[babenek]

Description

Please include a summary of the change and which is fixed.

• Add NTLM token pattern
• Fix ValuePatternCheck to skip 0x00 or 0xFF sequences in base64 values
• Fix ValueAllowlistCheck to match a value starts with $
• Fix ValueSimilarityCheck to 75% similarity with SequenceMatcher

How has this been tested?

Please describe the tests that you ran to verify your changes.

• UnitTest
• Benchmark

[codecov-commenter]

Codecov Report

❌ Patch coverage is 96.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 92.26%. Comparing base (c126863) to head (67cb1d7).

Files with missing lines	Patch %	Lines
credsweeper/filters/value_similarity_check.py	92.30%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #789      +/-   ##
==========================================
- Coverage   92.26%   92.26%   -0.01%     
==========================================
  Files         141      141              
  Lines        5704     5713       +9     
  Branches      925      929       +4     
==========================================
+ Hits         5263     5271       +8     
  Misses        286      286              
- Partials      155      156       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[Pomidorry]

[Yullia]

Approved