TIKA-1180: Add MatroskaDetector for improved MKV/WEBM detection

[sirajahmadzai]

This PR introduces a MatroskaDetector to more accurately identify MKV and WEBM files based on EBML headers and DocType strings. It improves detection in cases where:

• File extensions are missing
• DocType is compressed, shifted, or partially missing
• Signatures in tika-mimetypes.xml alone are insufficient

Includes:

• MatroskaDetector.java
• Test file: MatroskaDetectorTest.java
• META-INF/services/org.apache.tika.detect.Detector entry

Benchmarked against:

• Default Tika
• Wladimir Leite's mime-type additions
• This detector

Results indicate this approach improves detection accuracy in nuanced cases not handled by mime magic alone.