Add support for ignoring specific characters during masking in FixedLengthMasker

[ehayik]

Why

Add support to configure fixed-length masker to ignore specified characters during the masking process:

var masker = Masker.fixedLength()
    .ignore('-')
    .build();

var ssn = "123-45-6789";
var maskedSsn = masker.apply(ssn);
// Result: "***-**-****"

How

• Updated FixedLengthMasker class to support characters ignoring
  • Added a new field charToIgnore and its corresponding constructor parameter.
  • Implemented new methods to handle masking while ignoring specified characters.
  • Updated logic in the existing methods to account for the charToIgnore feature.
  • Introduced a new method ignore(char) in Builder for specifying a character to ignore during masking.
• Added tests to ensure the new feature works with different configurations.
• Verified masking behavior when ignoring specified characters with prefix/suffix preservation.

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
97.9% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud