Add ATSC PSIP parsing and guide views

[znbsf]

Summary

This adds ATSC PSIP support, including STT, MGT, TVCT/CVCT, EIT, ETT, and RRT parsing, plus ATSC descriptor support and UI summaries for PSIP-driven program/channel information.

Highlights:

• Add ATSC PSIP table model under psi/atsc
• Add ATSC descriptors including service location, extended channel name, caption service, content advisory, AC-3/E-AC-3, genre, and related descriptors
• Link VCT, PAT, and PMT information for ATSC channel/program summaries
• Add ATSC EIT/ETT timeline/grid style guide views while preserving DVB EIT behavior
• Add MGT/STT summary views
• Add ATSC parser tests and sample-section coverage

DVB compatibility notes

The existing DVB behavior is kept as the primary path:

• DVB service names still come from SDT first
• ATSC VCT names are only used as fallback
• EIT View uses DVB EIT data first and falls back to ATSC EIT only when DVB EIT data is absent
• ATSC private audio handling is limited to streams where PSIP is present

Validation

• mvn test passes: 71 tests, 0 failures, 0 errors
• mvn -Dmaven.test.skip=true package passes
• git diff --check upstream/master...HEAD passes

[znbsf]

A few compatibility notes for review:

• Existing DVB behavior should remain the primary path. DVB service names are still resolved from SDT first; ATSC VCT names are only used as a fallback.
• The EIT View keeps using the existing DVB EIT data when present. It only falls back to ATSC EIT/PSIP data when no DVB EIT events are available.
• ATSC private descriptors are only selected for ATSC PSIP table ids, so regular DVB private descriptor handling should not be affected.
• ATSC private audio stream handlers for stream types such as 0x81/0x87 are limited to streams where PSIP tables are present.
• The VCT/PAT/PMT linkage is used to improve ATSC channel/program labels and summaries without changing DVB SDT-first naming.

Local validation:

• mvn test passes: 71 tests, 0 failures, 0 errors.
• mvn -Dmaven.test.skip=true package passes.
• git diff --check upstream/master...HEAD passes.

The added ATSC tests cover STT, MGT, TVCT/CVCT, EIT, ETT, RRT, ATSC descriptors, version/section handling, channel/event ETT separation, and the ATSC Programs / Channels summary model.

[EricBerendsen]

Thank you very much for this impressive PR. I don't have a lot of time right now, so it might take some time for me to review it. Looks like e very useful addition.

[znbsf]

Thank you! No rush at all. I appreciate you taking a look, and I’ll be happy to address any review comments whenever you get to it.