Exclusions option to filter urls

[chapmandu]

This pull request enhances the Sitemapper class by adding support for URL exclusion patterns and includes corresponding unit tests to ensure the new functionality works as expected.

Use Case

To enable filtering unwanted sitemap indexes/urls. Example: https://www.slamcity.com/sitemap.xml contains the same urls but in 20+ languages. Attempting to parse this sitemap as is causes Error fetching sitemap: Maximum call stack size exceeded

Enhancements to Sitemapper class:

• Added a new exclusions option to the constructor, allowing users to specify an array of regex patterns to exclude certain URLs. (src/assets/sitemapper.js) [1] [2]
• Implemented a new isExcluded method to check if a URL matches any of the exclusion patterns. (src/assets/sitemapper.js)
• Updated the URL filtering logic in the Sitemapper class to use the isExcluded method, ensuring excluded URLs are filtered out during sitemap processing. (src/assets/sitemapper.js) [1] [2]

Unit tests for exclusions:

• Added unit tests for the new exclusions option to verify that URLs matching the exclusion patterns are correctly filtered out. (src/tests/test.js)
• Added unit tests for the isExcluded method to ensure it handles various scenarios, including no exclusions, matching and non-matching URLs, complex regex patterns, and case sensitivity. (src/tests/test.js)

[seantomburke]

Appreciate the test section!